Revert "Revert "Force save on builds finish event""

Oh, how I love reverts of reverts!

We are experiencing problems with unfinished builds once again and I'm
not sure what's causing it, so I'll try this as a hackish fix again.

We may remove it when the real cause is found.

This reverts commit 657d6e2380734140fb3f5a08b5f6363ba35002bc.

Conflicts:
	spec/travis/model/build/states_spec.rb