Revert "Revert "Remove the `:coffee` and `:coffeescript` Haml filters""

This reverts commit b0145d76.

config/initializers/haml.rb

 Haml::Template.options[:ugly] = true
+
+# Remove the `:coffee` and `:coffeescript` filters
+#
+# See https://git.io/vztMu and http://stackoverflow.com/a/17571242/223897
+Haml::Filters.remove_filter('coffee')
+Haml::Filters.remove_filter('coffeescript')