Spec syntax improvements for core and fixed absent money spec.

Some spec updates and fixes for core, observe that regression test for #2396 still fails randomly so i just gave it an extra comment.

This is based on a fresh fork of master branch.

* https for rubygems in common_spree_dependencies.rb
* expect instead of lambda and other rspec syntax changes.
* removed nested module on some specs.
* removed a lot of unnecessary line breaks and white space.
* renamed money.rb to money_spec.rb so those tests are triggered also.