Turn on warning-is-error in sphinx build

Turn on the flag to ensure that future warnings in the doc build
trigger a build failure.

Change-Id: I6f8f096499c4c16c2d554d79a8c48648ff3e0e4a

doc/source/contributing.rst

@@ -1 +0,0 @@
-.. include:: ../../CONTRIBUTING.rst

doc/source/index.rst

@@ -7,9 +7,6 @@ Contents:
    :maxdepth: 2
 
    readme
-   installation
-   usage
-   contributing
 
 Indices and tables
 ==================

doc/source/installation.rst

@@ -1,12 +0,0 @@
-============
-Installation
-============
-
-At the command line::
-
-    $ pip install python-solumclient
-
-Or, if you have virtualenvwrapper installed::
-
-    $ mkvirtualenv python-solumclient
-    $ pip install python-solumclient

doc/source/readme.rst

@@ -1 +1 @@
-.. include:: ../README.rst
+.. include:: ../../README.rst

doc/source/usage.rst

@@ -1,7 +0,0 @@
-========
-Usage
-========
-
-To use python-solumclient in a project::
-
-	import solumclient

setup.cfg

@@ -32,6 +32,7 @@ console_scripts =
 source-dir = doc/source
 build-dir = doc/build
 all_files = 1
+warning-is-error = 1
 
 [upload_sphinx]
 upload-dir = doc/build/html