mock missing in install_requires

Created by: abrahammartin

https://github.com/uisautomation/django-automationcommon/blob/18615c2407cdbea497b14f2f517570c2a031a60c/setup.py#L20

mock missing in install_requires but it's used in https://github.com/uisautomation/django-automationcommon/blob/18615c2407cdbea497b14f2f517570c2a031a60c/automationcommon/tests/utils.py#L12