test(integration): add example app tests

This integration test will clone a repository, push the app and test if they're up. `local.deisapp.com` is hardcoded into the test suite, though, and should probably be refactored. Read in an envvar, perhaps?

Usage: start up a cluster, initialize it, run `deis clusters:create` and then run the test suite:

    $ go test -v ./test

The python app is expected to fail due to https://github.com/deis/deis/issues/1090, but the other apps should work.