juju-deployer switching to Python 3 breaks packages that expect to be able to import the Python 2 library

According to debian/control in https://code.launchpad.net/~tvansteenburgh/juju-deployer/juju-deployer-packaging:

Package: juju-deployer
Architecture: any
Depends: python3-juju-deployer
Description: A transitional package which depends on python-juju-deployer.

It appears that the intention was to have 'juju-deployer' depend on 'python-juju-deployer', not 'python3-juju-deployer' which is what happens. As a result of this, upgrading from an older version of 'juju-deployer' results in only the python3 version getting installed, which is breaking existing scripts which 'import deployer'.