Support messages in rust verifier for specification v3.0

[dallagi]

The version 3.0 of the pact specification introduces support for messages, as documented here.

However, the reference implementation of the verifier for the v3.0 specification does not appear to support messages.
When run against a v3 pact, the output is as follows:

Verifying a pact between <consumer> and <provider>
         WARNING: Pact file has no interactions

Looking at the code - even though I'm not really fluent in Rust - it looks like it only supports "standard" interactions.

In case it may be helpful, the example contract I was trying to validate via the cli verifier can be found here

Thank you!

[uglyog]

Message support was added with #74

[dallagi]

I just tested this functionality and indeed it works perfectly. Thanks a lot!