Fix Ember._suspendListeners

We need more tests around this code.
update s3 upload task and update Gemfile.lock dependencies

Stops the error of "ember.prod.prod.js" not found on Travis, and also
updates the Gemfile to use the new gzip stuff for uploading to s3.
Merge pull request #3164 from fivetanley/new-s3-config

update s3 upload task and update Gemfile.lock dependencies