Updates ice_nine dependency to >= 0.6.0
Updates ice_nine dependency to >= 0.6.0

Details:
* ice_nine is still a new gem, we want to make sure we're up to date on
  any fixes and changes with it.
* Serf is also a relatively new and changing gem, so this update
  is to keep the pace going before we can actually call it really
  stable.

byu/serf