added --security-group option to launch script. Still adds + uses environment and gonzo groups, but this option can be used multiple times to specify additionals
Fixed tests after method rename
Fixed tests and line lengths
Renamed argument to --additional-security-group
Added -sg alias
Moved security group defaults definition to launch.py (the caller of launch_instance).

environment security group couldn't be defined as an argument default as it depends on another argument
Removed debug print
Moved all security group declaration, including defaults, together into gonzo/scripts/launch.launch
Merged in additional security groups and openstack tagging fix
Tidied security group declaration area
Adjusted tests