bower.json no longer requires to be bumped

`version` is currently a moot prop since git tags are used instead. More
info at https://github.com/bower/bower.json-spec/commit/a325da3.

hooks/pre-commit

@@ -85,6 +85,5 @@ end
 bumper = Bumper.new([
 	Source.new('mustache.js', /mustache.version = '([\d\.]*)'/),
 	Source.new('mustache.js.nuspec', /<version>([\d\.]*)<\/version>/),
-	Source.new('bower.json', /"version": "([\d\.]*)"/)
 ])
 bumper.start