allow groups of commands to be specfied for run_post_deploy commands
ensure groups config key is explictly made an Array
ensure missing groups are reported on
add error checking to validate whether passed in group exists in config, and change logic for looping of commands
add logic to handle missing groups
ensure ordering is consistent
change logic to unless instead of if, to ensure readability, and consistency
Merge pull request #2 from madAndroid/master

Change configuration to allow groups of commands to be run in run_post_deploy