Set Pillow==2.9.0
Set Pillow==2.9.0

Pillow version 3.0.x (the current version on from pip) doesn't seem to build/install correctly on our vagrant box, so we need to stick it at 2.9.0.
thunsaker/cloudpebble,thunsaker/cloudpebble,pebble/cloudpebble,pebble/cloudpebble,thunsaker/cloudpebble,pebble/cloudpebble,thunsaker/cloudpebble,pebble/cloudpebble,pebble/cloudpebble