Make the git:remote command print out the remote's value even if the remote already exists

[arschles]

Currently, the output looks like this:

ENG000656:k8s-claimer aaronschlesinger$ deis git:remote
fatal: remote deis already exists.
Error: exit status 128

Would be nicer if it printed out what the remote should be, but it could still exit non-zero

[Joshua-Anderson]

Even better, we could do something like this:

$ deis git:remote
fatal: remote deis already exists and is not set to the expected url.
Got remote deis ssh://git@deis-builder.test.com:2222/oldapp.git
Expected remote deis ssh://git@deis-builder.test.com:2222/newapp.git
Please run 'deis git:remote -f` to overwrite
$ deis git:remote -f
Git remote deis ssh://git@deis-builder.test.com:2222/newapp.git added.
$ deis get:remote
Git remote deis already exists and is set correctly