* Removes future from python-exp v3 sample
* Removes future from python-exp v2 sample
* Deletes future from remaining python-exp files
* Removes six from python-exp templates
* Removes six from python-exp samples
* Removes mock from python-exp
* Python-exp switched to py3
* Removes python 2.7 for python-exp ci testing
* Requires python>=3.3 for python-exp
* Reverts unnecessary changes to two templates