Fix Generator repository storage version check for incoming Cluster

Closes #320 (closed)

Details per issue above: when Gitaly Cluster is set up, the target environment has two repo storages, one unused one named default and another called storage-1 (Gitaly Cluster). We need to update repository storage version check to always check the environment ignoring storage count.

Additional small change: use new small project tarball that was added to performance-data