DEV: add a note about sprockets being held back

We want to upgrade to version 4, but it does not work atm.

Gemfile

@@ -28,6 +28,10 @@ else
   gem 'sprockets-rails'
 end
 
+# TODO: At the moment Discourse does not work with Sprockets 4, we would need to correct internals
+# This is a desired upgrade we should get to.
+gem 'sprockets', '3.7.2'
+
 # this will eventually be added to rails,
 # allows us to precompile all our templates in the unicorn master
 gem 'actionview_precompiler', require: false

Gemfile.lock

@@ -390,7 +390,7 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sprockets (4.0.0)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.1)
@@ -540,6 +540,7 @@ DEPENDENCIES
   shoulda-matchers
   sidekiq
   simplecov
+  sprockets (= 3.7.2)
   sprockets-rails
   sshkey
   stackprof