Summary:
Gets all the pieces in place to automatically publish snapshot artifacts after
successful travis build.
I'll test the actual publishing in a separate branch and then flip the switch in
a separate diff when it's ready.
Reviewed By: emilsjolander
Differential Revision: D5028239
fbshipit-source-id: c57d02a1dee41c84001bd17821b050c8c9aa4134
