For some reason, database key was treated differently in configparser object
in python 3.4.2. In Python 3.4.5 everything is fine. Fixed the defaults to
make sure all string options are treated equally.
Python envs used till now python3 for testing, now version of python
depends on the environment - for py2* python 2.7 will be used, and for
py3* appropriate python3 version will be used.
Also, added mock module for python2 envs.