problem using cloudify extension with dev branch

[DeWayne Filppi]

I see the following when trying to install the cloudify extension with the
ARIA-1 branch:

Installing collected packages: apache-ariatosca, aria-extension-cloudify
Found existing installation: apache-ariatosca 0.2.0
Uninstalling apache-ariatosca-0.2.0:

Then it fails.