Version bump to 0.19.0 (googleapis#333)

Version bump (googleapis#320)

Bump version (googleapis#313)

Bump the version (googleapis#309)

Bump generator version to 0.16 and required python version of the generated surface to 3.6

Bump version to 0.15.0 (googleapis#275)

Update version in setup.py to 0.14.0 (googleapis#259)

Initial sample generation documentation (googleapis#184)

Bump version to 0.12.0 (googleapis#156)

[fix] Alphabetically sort lines in a few more spots. (googleapis#155)

Add an autopep8 CI task and run autopep8 on all py files (googleapis#146

)