Bump version number on master

Merge pull request google#2106 from rachel-fenichel/november_rebuild

Rebuild to include blockToDom fix; bump version number

Merge pull request google#2095 from google/rc/Oct_18

October 2018 release

Merge pull request google#2042 from google/rc/sept_2018

September 2018 patch release

Merge branch 'master' into rc/august_2018