Add post-merge capability to pre-commit-hook.rb

This will make it possible to run a post-merge check when
pre-commit-hook.rb is referenced as a symlink from .git/hooks/post-merge

The kind of check you're going to do is entirely dependant on the
basename of the file, which is a little weird but convenient.

Verification is a little tricky on this. Coming soon.
Remove the broken SPOTCHECK_RECENT stuff
Also remove SPOTCHECK_RECENT from travis.
Add a new .travis.yml
Let's not screw up the .travis.yml
Okay just run it once
Can we test the modules before the bundle install?
Be explicit about which mode we're in.
Land todb-r7#3 for some final testing