(spec) Initial rspec-beaker testing scaffolding

This allows basic beaker testing to be performed inside the beaker
testing framework. (thanks @nibalizer)!

Closes: #20
(spec) remove unused rspec-system files

(we use now acceptance and beaker)

Refs: #20
(cherry picked from commit 275901ac9b720a844d931bea9ea5f53937bca5ca)