docker-machine rm hangs if server doesn't exist

[karser]

I tried the binary v1.4-dev from this PR #85 (comment)

➜  Downloads docker-machine rm scw2
About to remove scw2
WARNING: This action will delete both local reference and remote instance.
Are you sure? (y/n): y
^C
➜  Downloads docker-machine rm scw2 --force
About to remove scw2
WARNING: This action will delete both local reference and remote instance.
^C