Connect use json

[jonatas]

I updated from static examples to use from connect.json on x-common project.

It was merged recently: exercism/problem-specifications#297.

[petertseng]

Everything here looks OK.

Probably would be good if commit messages all mention "connect" somewhere.

I added two cases to connect.json

I am wondering whether this exercise should get a testVersion now, since solutions made before this PR will not pass the test suite after this PR.

(testVersion like https://github.com/exercism/xgo/blob/master/exercises/leap/leap.go and https://github.com/exercism/xgo/blob/master/exercises/leap/leap_test.go )

[petertseng]

we would want the testVersion to go in example.go so that submitted solutions have to show their testVersion (allowing reviewers of the code to easily see what version of the tests a solution was coded against). Putting it in cases_test.go would mean that nobody has to declare it

[petertseng]

I'm fine with everything I see here, and I asume if anyone else had anything to say I expect they should have said something earlier since this PR has been here for a few days.

Some final things to check on, and then I'll merge. This will happen within 24 hours, and you can and should feel justified in prodding me if I haven't done that.

Note: I plan to squash all commits into one before I merge, since this only really makes sense as one commit.