Add Openstack SSL Support

Allow Openstack connections to be protected with SSL.

Additionally, remove some unused methods in `EmsOpenstack`.

WIP: Looking at how to add tests for this.

Rebased: included tests and fixed a problem with the raw_connect method.

Rebased for rubocop
or rather, everything ultimately calls .connect on an EMS, which in turn calls .raw_connect (or at least it's supposed to)