Add Barge to dependancies
Adds access_token to config
Inject the barge client instead of digital_ocean
We need to specify to look for droplets

The API returns with an array of 3 elements:
droplets, links, meta

We really care about the droplets part for now, we can do clever stuff with the other data later :+1:
Change configuration to check for access_token
Move all client injections to barge
Merge branch 'api2_changes' of https://github.com/pearkes/tugboat into api2_changes

Conflicts:
	tugboat.gemspec