Revert "Revert "Update service docs""

This reverts commit 7ba28c0207.

docs/source/services.md

@@ -54,7 +54,7 @@ If a service is also to be managed by the Hub, it has a few extra options:
         externally.
       - If a command is specified for launching the Service, the Service will
         be started and managed by the Hub.
-- `env: dict` - environment variables to add to the current env
+- `environment: dict` - additional environment variables for the Service.
 - `user: str` - the name of a system user to manage the Service. If
   unspecified, run as the same user as the Hub.
 
@@ -99,7 +99,7 @@ c.JupyterHub.services = [
 A Hub-Managed Service may also be configured with additional optional
 parameters, which describe the environment needed to start the Service process:
 
-- `env: dict` - additional environment variables for the Service.
+- `environment: dict` - additional environment variables for the Service.
 - `user: str` - name of the user to run the server if different from the Hub.
    Requires Hub to be root.
 - `cwd: path` directory in which to run the Service, if different from the

jupyterhub/app.py

@@ -454,7 +454,7 @@ class JupyterHub(Application):
                     'name': 'formgrader',
                     'url': 'http://127.0.0.1:1234',
                     'token': 'super-secret',
-                    'env': 
+                    'environment': 
                 }
             ]
         """

jupyterhub/services/service.py

@@ -124,8 +124,8 @@ class Service(LoggingConfigurable):
         Only use this if the service should be a subprocess.
         If command is not specified, it is assumed to be managed
         by a
-    - env: dict
-        environment variables to add to the current env
+    - environment: dict
+        Additional environment variables for the service.
     - user: str
         The name of a system user to become.
         If unspecified, run as the same user as the Hub.