Fix testenv keypair creation logic

If we no longer have the private key for the testenv on disk
go ahead and remove it from nova. Fix variable names so we can
successfully create a key pair now.
Do not append line to hosts file multiple times, use Ubuntu standard 127.0.1.1 for the FQDN of this host
Merge pull request #239 from blueboxgroup/fix-setup-keypair

Fix setup keypair