Extract a function to post status for non-mergeable PR
Reorganize logic so state change event can be handled and not causing infinite loop
Add test for state change handler for non-mergeable PR
No need to handle state change event, travis won't start if the commit status is not mergeable.
Merge branch 'master' of github.com:numenta/nupic.tools into 85-provide-non-mergeable-status
Merge pull request #1 from rhyolight/85-provide-non-mergeable-status

Merged in master
Merge pull request #99 from utensil/85-provide-non-mergeable-status

Improvements on #87