Add test documentation for docs tox target

Enable sphinx to generate documentation from docstrings by running
'tox -e docs'.

Change-Id: I5996e5f07493f69f14172b4bb0535852e89d5456
diff --git a/neutron_tempest_plugin/common/shell.py b/neutron_tempest_plugin/common/shell.py
index eebb07d..073bf55 100644
--- a/neutron_tempest_plugin/common/shell.py
+++ b/neutron_tempest_plugin/common/shell.py
@@ -47,18 +47,18 @@
     :param timeout: command execution timeout in seconds
 
     :param check: when False it doesn't raises ShellCommandFailed when
-    exit status is not zero. True by default
+       exit status is not zero. True by default
 
     :returns: STDOUT text when command execution terminates with zero exit
-    status.
+       status.
 
     :raises ShellTimeoutExpired: when timeout expires before command execution
-    terminates. In such case it kills the process, then it eventually would
-    try to read STDOUT and STDERR buffers (not fully implemented) before
-    raising the exception.
+       terminates. In such case it kills the process, then it eventually would
+       try to read STDOUT and STDERR buffers (not fully implemented) before
+       raising the exception.
 
     :raises ShellCommandFailed: when command execution terminates with non-zero
-    exit status.
+       exit status.
     """
     ssh_client = ssh_client or SSH_PROXY_CLIENT
     if timeout:
diff --git a/neutron_tempest_plugin/common/ssh.py b/neutron_tempest_plugin/common/ssh.py
index 4cb1474..700d21b 100644
--- a/neutron_tempest_plugin/common/ssh.py
+++ b/neutron_tempest_plugin/common/ssh.py
@@ -133,7 +133,7 @@
         :returns: paramiko.Client connected to remote server.
 
         :raises tempest.lib.exceptions.SSHTimeout: in case it fails to connect
-        to remote server.
+           to remote server.
         """
         return super(Client, self)._get_ssh_connection(*args, **kwargs)
 
diff --git a/neutron_tempest_plugin/common/utils.py b/neutron_tempest_plugin/common/utils.py
index ab99db9..c62aa78 100644
--- a/neutron_tempest_plugin/common/utils.py
+++ b/neutron_tempest_plugin/common/utils.py
@@ -73,7 +73,7 @@
     """Wait until callable predicate is evaluated as True
 
     :param predicate: Callable deciding whether waiting should continue.
-    Best practice is to instantiate predicate with functools.partial()
+       Best practice is to instantiate predicate with functools.partial()
     :param timeout: Timeout in seconds how long should function wait.
     :param sleep: Polling interval for results in seconds.
     :param exception: Exception instance to raise on timeout. If None is passed