You probably created your domain and application through the web interface. This is an issue we are working through now - sorry we haven't gotten to it yet - it will be fixed in the next couple of sprints. The problem is that your SSH env has not been set up to work with the RHC tools yet. They expect a configure file in the .ssh directory to specify which key talks to the *.rhcloud.com domain. This KB article may help you get started:
https://openshift.redhat.com/community/kb/kb-e1034-ssh-facts...
Again, my apologies and we are actively working on that story right now.