Logic in upload_docs will only trigger docs build if no docs dir was...

Logic in upload_docs will only trigger docs build if no docs dir was specified, so explicitly build during release. Fixes #524.

setup.cfg

@@ -9,7 +9,7 @@ tag_date = 1
 
 [aliases]
 clean_egg_info = egg_info -RDb ''
-release = clean_egg_info sdist bdist_wheel
+release = clean_egg_info sdist bdist_wheel build_sphinx
 source = register sdist binary
 binary = bdist_egg upload --show-response
 test = pytest