Replace python 2 with python 3 in ansible-operator base image

[ejez]

When using image quay.io/operator-framework/ansible-operator:master as a base image for an ansible operator and adding python packages in the dockerfile with pip I get the following deprecation message:

DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020.
Please upgrade your Python as Python 2.7 won't be maintained after that date.
A future version of pip will drop support for Python 2.7.
More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support

[camilamacedo86]

Closing it. The fix is merged.