The stdlib version of the json library is more recent than the 3.5.3
version we are pinning in `requirements.txt`
There is no reason to use it.
Closes#6940
The `unittest2` package is simply a backport of `unittest` from the
Standard Library of Python 2.7 to previous versions.
There is no reason to use it any longer.
Closes#6941
RPM packages did not pass the tests because the centos prompt changed
and thus did not match the regexp anymore. We now explicitely specify
the prompt in our Dockerfiles to prevent such issues.