(QENG-124) get rid of add_master_entry

- execution of add_master_entry has been off by default for a while, so
  we know that this code is no longer necessary, this is just clean up
Merge pull request #314 from anodelman/maint

(QENG-124) get rid of add_master_entry
Add ability to pass ports as well as roles to EC2 provisioner
Add test coverage for EC2 port feature