Remove leftover references to coffeescript from comments and docs.

app/assets/javascripts/application.js

 /* eslint-disable */
 // This is a manifest file that'll be compiled into including all the files listed below.
-// Add new JavaScript/Coffee code in separate files in this directory and they'll automatically
+// Add new JavaScript code in separate files in this directory and they'll automatically
 // be included in the compiled file accessible from http://example.com/assets/application.js
 // It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
 // the compiled file.

app/assets/javascripts/graphs/graphs_bundle.js

 /* eslint-disable */
 // This is a manifest file that'll be compiled into including all the files listed below.
-// Add new JavaScript/Coffee code in separate files in this directory and they'll automatically
+// Add new JavaScript code in separate files in this directory and they'll automatically
 // be included in the compiled file accessible from http://example.com/assets/application.js
 // It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
 // the compiled file.

app/assets/javascripts/network/network_bundle.js

 /* eslint-disable */
 // This is a manifest file that'll be compiled into including all the files listed below.
-// Add new JavaScript/Coffee code in separate files in this directory and they'll automatically
+// Add new JavaScript code in separate files in this directory and they'll automatically
 // be included in the compiled file accessible from http://example.com/assets/application.js
 // It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
 // the compiled file.

doc/development/gotchas.md

@@ -41,9 +41,9 @@ Rubocop](https://gitlab.com/gitlab-org/gitlab-ce/blob/8-4-stable/.rubocop.yml#L9
 [Exception]: http://stackoverflow.com/q/10048173/223897
-## Don't use inline CoffeeScript/JavaScript in views
-Using the inline `:coffee` or `:coffeescript` Haml filters comes with a
+## Don't use inline JavaScript in views
+Using the inline `:javascript` Haml filters comes with a
 performance overhead. Using inline JavaScript is not a good way to structure your code and should be avoided.
 _**Note:** We've [removed these two filters](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/config/initializers/hamlit.rb)
@@ -51,9 +51,7 @@ in an initializer._
 ### Further reading
-- Pull Request: [Replace CoffeeScript block into JavaScript in Views](https://git.io/vztMu)
 - Stack Overflow: [Why you should not write inline JavaScript](http://programmers.stackexchange.com/questions/86589/why-should-i-avoid-inline-scripting)
-- Stack Overflow: [Performance implications of using :coffescript filter inside HAML templates?](http://stackoverflow.com/a/17571242/223897)
 ## ID-based CSS selectors need to be a bit more specific

doc/development/testing.md

@@ -36,8 +36,8 @@ the command line via `bundle exec teaspoon`, or via a web browser at
 `http://localhost:3000/teaspoon` when the Rails server is running.
 - JavaScript tests live in `spec/javascripts/`, matching the folder structure of
-  `app/assets/javascripts/`: `app/assets/javascripts/behaviors/autosize.js.coffee` has a corresponding
-  `spec/javascripts/behaviors/autosize_spec.js.coffee` file.
+  `app/assets/javascripts/`: `app/assets/javascripts/behaviors/autosize.js.es6` has a corresponding
+  `spec/javascripts/behaviors/autosize_spec.js.es6` file.
 - Haml fixtures required for JavaScript tests live in
   `spec/javascripts/fixtures`. They should contain the bare minimum amount of
   markup necessary for the test.

spec/javascripts/spec_helper.js

@@ -28,7 +28,7 @@
 // setTimeout(Teaspoon.execute, 1000)
 // Matching files
 // By default Teaspoon will look for files that match
-// _spec.{js,js.coffee,.coffee}. Add a filename_spec.js file in your spec path
+// _spec.{js,js.es6}. Add a filename_spec.js file in your spec path
 // and it'll be included in the default suite automatically. If you want to
 // customize suites, check out the configuration in teaspoon_env.rb
 // Manifest