Remove ruby dependecy

[andrewspinks]

Switch to using native mock service:
https://github.com/pact-foundation/pact-reference

[bethesque]

Hey Spinks, want to use the standalone build of the mock service? Then you can remove the ruby dependency.

[bethesque]

This is how the python one does it https://github.com/pact-foundation/pact-python/blob/master/setup.py

[surpher]

We've started using https://github.com/pact-foundation/homebrew-pact-ruby-standalone.

This issue can be closed if I'm not mistaken?

[surpher]

Task:

• remove .ruby-version file from repo to close this issue

[andrewspinks]

This was originally more about switching to the native library (https://github.com/pact-foundation/pact-reference), so there are no separate dependencies that needed to be installed. But happy for a new, different issue to be opened about that if we want to go down that route.