Dalli 2.1 not reading ENV

If you're running Dalli 2.1 on Heroku, there seems to be a problem with Dalli not reading the config variables, causing it to use localhost instead.

This (https://github.com/mperham/dalli/pull/266) seems to fix it, so you'll want to make sure your gem is up to date, or temporarily revert to an older version.