diff --git a/Makefile b/Makefile
index 358e456b..239a63f0 100644
--- a/Makefile
+++ b/Makefile
@@ -52,6 +52,16 @@ build-test-all: $(foreach I,$(ALL_IMAGES),arch_patch/$(I) build/$(I) test/$(I) )
 check-outdated/%: ## check the outdated conda packages in a stack and produce a report (experimental)
 	@TEST_IMAGE="$(OWNER)/$(notdir $@)" pytest test/test_outdated.py
 
+cont-clean-all: cont-stop-all cont-rm-all ## clean all containers (stop + rm)
+
+cont-stop-all: ## stop all containers
+	@echo "Stopping all containers ..."
+	-docker stop -t0 $(shell docker ps -a -q) 2> /dev/null
+
+cont-rm-all: ## remove all containers
+	@echo "Removing all containers ..."
+	-docker rm --force $(shell docker ps -a -q) 2> /dev/null
+
 dev/%: ARGS?=
 dev/%: DARGS?=
 dev/%: PORT?=8888
@@ -61,6 +71,20 @@ dev/%: ## run a foreground container for a stack
 dev-env: ## install libraries required to build docs and run tests
 	pip install -r requirements-dev.txt
 
+img-clean: img-rm-dang img-rm ## clean dangling and jupyter images
+
+img-list: ## list jupyter images
+	@echo "Listing $(OWNER) images ..."
+	docker images "$(OWNER)/*"
+
+img-rm:  ## remove jupyter images
+	@echo "Removing $(OWNER) images ..."
+	-docker rmi --force $(shell docker images --quiet "$(OWNER)/*") 2> /dev/null
+
+img-rm-dang: ## remove dangling images (tagged None)
+	@echo "Removing dangling images ..."
+	-docker rmi --force $(shell docker images -f "dangling=true" -q) 2> /dev/null
+
 docs: ## build HTML documentation
 	make -C docs html
 
@@ -71,11 +95,17 @@ n-docs-diff: ## number of docs/ files changed since branch from master
 n-other-diff: ## number of files outside docs/ changed since branch from master
 	@git diff --name-only $(DIFF_RANGE) -- ':!docs/' | wc -l | awk '{print $$1}'
 
-run/%: ## run a bash in interactive mode in a stack
-	docker run -it --rm $(OWNER)/$(notdir $@) $(SHELL)
+pull/%: DARGS?=
+pull/%: ## pull a jupyter image
+	docker pull $(DARGS) $(OWNER)/$(notdir $@)
 
+run/%: DARGS?=
+run/%: ## run a bash in interactive mode in a stack
+	docker run -it --rm $(DARGS) $(OWNER)/$(notdir $@) $(SHELL)
+
+run-sudo/%: DARGS?=
 run-sudo/%: ## run a bash in interactive mode as root in a stack
-	docker run -it --rm -u root $(OWNER)/$(notdir $@) $(SHELL)
+	docker run -it --rm -u root $(DARGS) $(OWNER)/$(notdir $@) $(SHELL)
 
 tx-en: ## rebuild en locale strings and push to master (req: GH_TOKEN)
 	@git config --global user.email "travis@travis-ci.org"
diff --git a/minimal-notebook/test/test_nbconvert.py b/minimal-notebook/test/test_nbconvert.py
index 653deae9..5dc61f0d 100644
--- a/minimal-notebook/test/test_nbconvert.py
+++ b/minimal-notebook/test/test_nbconvert.py
@@ -16,7 +16,7 @@ def test_nbconvert(container, format):
     cont_data_dir = "/home/jovyan/data"
     test_file = "notebook1"
     output_dir = "/tmp"
-    LOGGER.info(f"Converting example notebook to {format.upper()} ...")
+    LOGGER.info(f"Test that an example notebook can be converted to {format.upper()} ...")
     command = f"jupyter nbconvert {cont_data_dir}/{test_file}.ipynb --output-dir {output_dir} --to {format}"
     c = container.run(
         volumes={host_data_dir: {"bind": cont_data_dir, "mode": "ro"}},
@@ -24,8 +24,8 @@ def test_nbconvert(container, format):
         command=["start.sh", "bash", "-c", command],
     )
     rv = c.wait(timeout=30)
-    assert rv == 0 or rv["StatusCode"] == 0
+    assert rv == 0 or rv["StatusCode"] == 0, f"Command {command} failed"
     logs = c.logs(stdout=True).decode("utf-8")
     LOGGER.debug(logs)
-    assert f"{output_dir}/{test_file}.{format}" in logs
-
+    expected_file = f"{output_dir}/{test_file}.{format}"
+    assert expected_file in logs, f"Expected file {expected_file} not generated"
diff --git a/scipy-notebook/test/data/matplotlib_1.py b/scipy-notebook/test/data/matplotlib_1.py
new file mode 100644
index 00000000..9b04e5de
--- /dev/null
+++ b/scipy-notebook/test/data/matplotlib_1.py
@@ -0,0 +1,24 @@
+# Matplotlit: Create a simple plot example.
+# Refs: https://matplotlib.org/3.1.1/gallery/lines_bars_and_markers/simple_plot.html
+
+# Optional test with [Matplotlib Jupyter Integration](https://github.com/matplotlib/ipympl)
+# %matplotlib widget
+import matplotlib
+import matplotlib.pyplot as plt
+import numpy as np
+import os
+
+# Data for plotting
+t = np.arange(0.0, 2.0, 0.01)
+s = 1 + np.sin(2 * np.pi * t)
+
+fig, ax = plt.subplots()
+ax.plot(t, s)
+
+ax.set(xlabel='time (s)', ylabel='voltage (mV)',
+       title='About as simple as it gets, folks')
+ax.grid()
+# Note that the test can be run headless by checking if an image is produced
+file_path = os.path.join("/tmp", "test.png")
+fig.savefig(file_path)
+print(f"File {file_path} saved")
\ No newline at end of file
diff --git a/scipy-notebook/test/test_matplotlib.py b/scipy-notebook/test/test_matplotlib.py
new file mode 100644
index 00000000..ed5a319d
--- /dev/null
+++ b/scipy-notebook/test/test_matplotlib.py
@@ -0,0 +1,35 @@
+# Copyright (c) Jupyter Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+import logging
+
+import pytest
+import os
+
+LOGGER = logging.getLogger(__name__)
+
+
+def test_matplotlib(container):
+    """Test that matplotlib is able to plot a graph and write it as an image"""
+    host_data_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), "data")
+    cont_data_dir = "/home/jovyan/data"
+    test_file = "matplotlib_1.py"
+    output_dir = "/tmp"
+    LOGGER.info(f"Test that matplotlib is able to plot a graph and write it as an image ...")
+    command = "sleep infinity"
+    running_container = container.run(
+        volumes={host_data_dir: {"bind": cont_data_dir, "mode": "ro"}},
+        tty=True,
+        command=["start.sh", "bash", "-c", command],
+    )
+    command = f"python {cont_data_dir}/{test_file}"
+    cmd = running_container.exec_run(command)
+    assert cmd.exit_code == 0, f"Command {command} failed"
+    LOGGER.debug(cmd.output.decode("utf-8"))
+    # Checking if the file is generated
+    # https://stackoverflow.com/a/15895594/4413446
+    expected_file = f"{output_dir}/test.png"
+    command = f"test -s {expected_file}"
+    cmd = running_container.exec_run(command)
+    assert cmd.exit_code == 0, f"Command {command} failed"
+    LOGGER.debug(cmd.output.decode("utf-8"))
diff --git a/scipy-notebook/test/test_pandas.py b/scipy-notebook/test/test_pandas.py
index f054963a..0da7aaf1 100644
--- a/scipy-notebook/test/test_pandas.py
+++ b/scipy-notebook/test/test_pandas.py
@@ -21,6 +21,6 @@ def test_pandas(container, name, command):
     LOGGER.info(f"Testing pandas: {name} ...")
     c = container.run(tty=True, command=["start.sh", "python", "-c", command])
     rv = c.wait(timeout=30)
-    assert rv == 0 or rv["StatusCode"] == 0
+    assert rv == 0 or rv["StatusCode"] == 0, f"Command {command} failed"
     logs = c.logs(stdout=True).decode("utf-8")
     LOGGER.debug(logs)
diff --git a/tensorflow-notebook/test/test_tensorflow.py b/tensorflow-notebook/test/test_tensorflow.py
index 680343c7..f5a6910f 100644
--- a/tensorflow-notebook/test/test_tensorflow.py
+++ b/tensorflow-notebook/test/test_tensorflow.py
@@ -25,6 +25,6 @@ def test_tensorflow(container, name, command):
     LOGGER.info(f"Testing tensorflow: {name} ...")
     c = container.run(tty=True, command=["start.sh", "python", "-c", command])
     rv = c.wait(timeout=30)
-    assert rv == 0 or rv["StatusCode"] == 0
+    assert rv == 0 or rv["StatusCode"] == 0, f"Command {command} failed"
     logs = c.logs(stdout=True).decode("utf-8")
     LOGGER.debug(logs)
diff --git a/test/test_notebook.py b/test/test_notebook.py
index 51746fed..548c272d 100644
--- a/test/test_notebook.py
+++ b/test/test_notebook.py
@@ -1,9 +1,10 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 
+
 def test_secured_server(container, http_client):
     """Notebook server should eventually request user login."""
     container.run()
-    resp = http_client.get('http://localhost:8888')
+    resp = http_client.get("http://localhost:8888")
     resp.raise_for_status()
-    assert 'login_submit' in resp.text
+    assert "login_submit" in resp.text, "User login not requested"