Add spark notebook tests and change examples

* Test added for all kernels
* Same examples as provided in the documentation (`specifics.md`)
* Used the same use case for all examples: sum of the first 100 whole numbers

Note: I've not automatically tested `local_sparklyr.ipynb` since it creates by default the `metastore_db` dir and the `derby.log` file in the working directory. Since I mount it in `RO` it's not working. I'm struggling to set it elsewhere...

all-spark-notebook/test/test_spark_notebooks.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__)
+
+
+@pytest.mark.parametrize(
+    "test_file",
+    # TODO: add local_sparklyr
+    ["local_pyspark", "local_spylon", "local_toree", "local_sparkR"],
+)
+def test_nbconvert(container, test_file):
+    """Check if Spark notebooks can be executed"""
+    host_data_dir = os.path.join(os.path.dirname(os.path.realpath(__file__)), "data")
+    cont_data_dir = "/home/jovyan/data"
+    output_dir = "/tmp"
+    timeout_ms = 600
+    LOGGER.info(f"Test that {test_file} notebook can be executed ...")
+    command = f"jupyter nbconvert --to markdown --ExecutePreprocessor.timeout={timeout_ms} --output-dir {output_dir} --execute {cont_data_dir}/{test_file}.ipynb"
+    c = container.run(
+        volumes={host_data_dir: {"bind": cont_data_dir, "mode": "ro"}},
+        tty=True,
+        command=["start.sh", "bash", "-c", command],
+    )
+    rv = c.wait(timeout=timeout_ms / 10 + 10)
+    assert rv == 0 or rv["StatusCode"] == 0, f"Command {command} failed"
+    logs = c.logs(stdout=True).decode("utf-8")
+    LOGGER.debug(logs)
+    expected_file = f"{output_dir}/{test_file}.md"
+    assert expected_file in logs, f"Expected file {expected_file} not generated"