The server tests in digital ocean have been frequently timing out.
* https://travis-ci.org/fog/fog/jobs/20605301#L1030
* https://travis-ci.org/fog/fog/jobs/19765753#L1233
...and many more
Each timeout run wastes Travis resources and the time of the people who
have to check why their unrelated changes are failed.
We've even become so complacent about it, standard practice is to just
comment and merge.
So I'm disabling the tests until someone fixes it or we replace the
server tests with a cleaner approach, whichever comes first.
* Allows specifying public_key and private_key rather than public_key_path and private_key_path. Useful for Heroku where you don't have direct access to the filesystem and need to specify keys in environment variables.
* Handle case where droplet is locked pending events, DO support says
they are planning to expose something in the api to show these events.
Until then this is the best we have.
* Whitespace cleanup
* Refactor test helpers
* Use the collection helper for the digitalocean servers collection
