set up tox to run docs build with checker enabled

Use an environment variable to control when the extension is enabled
in conf.py.

Add settings to setup.cfg to control the build.

Add tox environment 'docs' to build HTML docs and then run spell
check.

Update the word list with more words that are used and should not
trigger a build failure.

Change-Id: I19b7e2134eb7961f9817fadf30de57ed82b855ef
Signed-off-by: Doug Hellmann <[email protected]>

docs/source/conf.py

@@ -28,7 +28,9 @@
 #
 # CANNOT ENABLE SPHINXCONTRIB.SPELLING because ReadTheDocs.org does not support
 # PyEnchant.
-#extensions = [ 'sphinxcontrib.spelling' ]
+extensions = []
+if os.getenv('ENABLE_SPELLING'):
+    extensions.append('sphinxcontrib.spelling')
 
 spelling_show_suggestions = True
 spelling_ignore_pypi_package_names = True

docs/source/spelling_wordlist.txt

@@ -1 +1,8 @@
+builtins
+reStructuredText
+sphinxcontrib
 tokenizer
+txt
+wikis
+wordlist
+Minhee

setup.cfg

@@ -35,3 +35,9 @@ namespace_packages =
 
 [aliases]
 release = egg_info -RDb ''
+
+[build_sphinx]
+all-files = 1
+warning-is-error = 1
+source-dir = docs/source
+build-dir = docs/build

tox.ini

@@ -19,3 +19,10 @@ commands=
 [testenv:pep8]
 deps=flake8
 commands=flake8 sphinxcontrib setup.py
+
+[testenv:docs]
+setenv =
+    ENABLE_SPELLING=1
+commands =
+    python setup.py build_sphinx
+    sphinx-build -b spelling docs/source docs/build