Add conditional python and coverage variable assignments.
Add conditional python and coverage variable assignments.

Enables make targets to use either python2 or python3 while preferring python3.
Also removed unncessary coverage reports. Unit testing coverage reporting was added to the runner script and functional testing does not have coverage reporting available.

Drudenhaus/aws-ec2rescue-linux,gregbdunn/aws-ec2rescue-linux,Drudenhaus/aws-ec2rescue-linux,Drudenhaus/aws-ec2rescue-linux,gregbdunn/aws-ec2rescue-linux,gregbdunn/aws-ec2rescue-linux