Revert "Allow a person to set their own _version.py for testing."

This reverts commit 21db84d5c073ff3580956a99b024c35ca29e3a96.
Fix publish tests
Revert "Revert "Allow a person to set their own _version.py for testing.""

This reverts commit 7d38a7837139a78bc0cca77a9a9ce977b47d5a79.