Better error reporting

[Michael Su]

The problem: 1) warnings are show at top as example below. can we make errors show at the top?

build   26-Oct-2017 16:49:26    [test:pact-with-swagger] 1 error(s)
build   26-Oct-2017 16:49:26    [test:pact-with-swagger]    spv.response.body.incompatible: 1
build   26-Oct-2017 16:49:26    [test:pact-with-swagger] 9 warning(s)
build   26-Oct-2017 16:49:26    [test:pact-with-swagger]    sv.warning: 9
build   26-Oct-2017 16:49:26    [test:pact-with-swagger] { warnings: 
build   26-Oct-2017 16:49:26    [test:pact-with-swagger]    [ { code: 'sv.warning',
build   26-Oct-2017 16:49:26    [test:pact-with-swagger]        message: 'Definition is defined but is not used: #/definitions/ListWrapperCallback',

2) Can we show the snippet of Swagger definition where you report the error? If there's a problem reporting, we often have to dig into the problematic definition from a large swagger file. If we can show the snippet of the swagger file, it would save a lot of time in trouble shooting.

3) Provide some easy to read error reporting in the logs that would tell us what is going wrong (eg: Id should be string, got number)