Improve error message when array is longer than expected

[bethesque]

See http://stackoverflow.com/questions/42948214/pact-verify-provider-what-does-pactunexpectedindex-mean/42988501

[R-M-F-at-C-A]

I would find the following clearer:

        "data": {
            "attributes": {
              "stuff": [
+                 {
+                    "foo": "bar",
+                    ... 
+                   "baz": "quok",
+                  }   
              ]
            }
          }

The description is pretty good though:

       Description of differences
       --------------------------------------
       * Actual array is too long and should not contain a Hash at $.data.attributes.stuff[0]

[bethesque]

Agreed, I like your suggested output.

The diff output will be replaced by whatever is in the shared rust implementation once that is integrated into the ruby codebase.

[YOU54F]

Believe this is resolved as per comments in #49 (comment)

The output now looks like

  1) Verifying a pact between Foo and Bar A retrieve thing request with GET /thing returns a response which has a matching body
     Failure/Error: expect(response_body).to match_term expected_response_body, diff_options, example
     
       Actual: {"company":"My Company","factories":[{"location":"Sydney","capacity":5},{"location":"Sydney","geographicCoords":"-0.145,1.4445","capacity":5}]}
     
       Diff
       --------------------------------------
       Key: - is expected 
            + is actual 
       Matching keys and values are not shown
       
        {
          "factories": [
            ... ,
       +    {
       +      "location": "Sydney",
       +      "geographicCoords": "-0.145,1.4445",
       +      "capacity": 5
       +    },
          ]
        }
       
       Description of differences
       --------------------------------------
       * Actual array is too long and should not contain a Hash at $.factories[1]

removing the confusing Pact:UnexpectedIndex and showing the additional contents which were not expected.

Checking the output of the same test using the pact_ffi library, which would be introduced by pact-foundation/pact-ruby#317

Failures:

1) Verifying a pact between V4-consumer and V4-provider - a retrieve thing request
    1.1) has a matching body
           $.factories -> Expected a List with 1 elements but received 2 elements

There were 1 pact failures