Add gifsicle to buildpacks.
Revert "Add gifsicle to buildpacks."

This reverts commit 1facbd9f7f60282f8e5b253a8de47b513417e36a.
Update grunt and grunt-contrib-imagemin.
Upgrade grunt-wiredep.
Remove wiredep cwd from Gruntfile.
Set production host to lunchhub.com.
Add rack-rewrite.
Get rack-rewrite working with RSpec.