Do the 'bower install' as an npm postinstall action, and add 'grunt
compass:dev', so all the proper prep is done via 'npm install'.
Set path for Grunt and Bower in package.json and trimmed bower from the .travis.yml file
Remove compass step from postinstall

(We don't otherwise need compass in our continuous integration scheme, and
it's not worth changing that for this small, documentable item.)
Merge pull request #15 from SpiderOak/consolidate-install-actions

Do the 'bower install' as an npm postinstall action, and add 'grunt