Fix the unused import error

The ununused import statement is now ignored by pyflakes and no error
is raised. The rtd-requirements.txt file now directly installs the
docs dependencies in one step instead of earlier two steps.

.travis.yml

@@ -131,7 +131,7 @@ install:
   - "[ $TESTS != lint ] || pip install pylint==1.1.0 pep8==1.5.7 flake8  astroid==1.3.8"
   # Install sphinx so that pylint will be able to import it
   - "[ $TESTS != lint ] || pip install sphinx==1.3.3"
-  # TODO: Pin Sphinx version to workaround http://trac.buildbot.net/ticket/3408
+  # Install docs dependencies for running the tests
   - "[ $TESTS != docs ] || pip install -e ./master[docs]"
 
 before_script:

master/docs/conf.py

@@ -22,7 +22,7 @@
 
 # -- General configuration -----------------------------------------------------
 try:
-    import sphinxcontrib.blockdiag
+    import sphinxcontrib.blockdiag  # noqa
 except ImportError:
     raise RuntimeError("sphinxcontrib.blockdiag is not installed. "
         "Please install documentation dependencies with `pip install buildbot[docs]`")

master/setup.py

@@ -430,6 +430,7 @@ def define_plugin_entries(groups):
             'Twisted[tls] ' + twisted_ver,
         ],
         'docs': [
+            # TODO: Pin Sphinx version to workaround http://trac.buildbot.net/ticket/3408
             'sphinx==1.3.3',
             'sphinxcontrib-blockdiag',
             'docutils>=0.8',

rtd-requirements.txt

@@ -1,7 +1,4 @@
 # Requirements list for building documentation on ReadTheDocs.
 
-# Install master.
--e master/
-
-# Install docs dependencies.
--e master[docs]
+# Install master with the docs dependencies
+-e master[docs]