Make build and external tests work with python3, so we can drop
the python2 dependency.
This should be merged shortly after osmo-python-tests was migrated to
python3, and the jenkins build slaves were (automatically) updated to
have the new osmo-python-tests installed.
Related: OS#2819
Depends: osmo-python-tests I3ffc3519bf6c22536a49dad7a966188ddad351a7
Change-Id: I344c49001fba23bdcfdef06ab174c52b60edd01c
Oliver Smith
Harald Welte