Initial attempt at using Service Worker

- Caches facebook profile pictures and static resources
- Removes django-compressor and commited bower_components
- rest fixes

static/app/styles/screen.scss

@@ -1,6 +1,6 @@
 @import "variables";
 @import "mixins";
-@import "../bower_components/bootstrap-sass-official/vendor/assets/stylesheets/bootstrap.scss";
+@import "../../bower_components/bootstrap-sass-official/vendor/assets/stylesheets/bootstrap.scss";
 @import "datepicker";
 
 body {