Build Testing approach using tcell simulation screen

[lawrencegripper]

Related issue
#86

Describe

This is WIP looking at building a simple to use integration testing approach for gocui. The aim is to allow input and assertion about the
resulting screen content.

Todo

• Update docs to show how to use this to test gocui
• [ ] Add some sample tests to the _examples not got time to complete this item atm.

[mjarkk]

Oh i'm just thinking of something wouldn't it be nice if we have tests for the examples?
If we have those users know how to write tests for their gocui programs and we can make our cd/ci stronger.

And can you add testing capabilities to the readme features section?

[lawrencegripper]

Yeah sounds good to me, I'll add a set of tests to one of the examples then reference to this from the docs showing how to run tests.

Playing around with how/what to expose, tests still look a bit busy so might add a few helper methods to make them nicer to write.

[lawrencegripper]

So I'm pretty happy with the way the tests have worked out (except I have a file called testing_test.go and some of the naming).

Be great to get some thoughts on this before I write up the docs. The testing_test.go should show how this can be used.

[lawrencegripper]

Any thoughts on this one? If we're happy with the approach I can finish off the docs and get this ready for review.

[mjarkk]

Ya this is looking good!

I've personally not written a lot of test so i'm probably not the one to tell whats right or wrong but from what i can see in the code it looks good and it seems we can expend on this code.

I would like to have this merged as the possibility to easily write tests is always better than no possibility (or is very hard) to test.

[lawrencegripper]

Think this should be all set, I've added some basic docs to the README and removed the usage of gomega

[mjarkk]

Code looks good, only some documentation i think could be changed

[mjarkk]

One last thing. Can you update to the latest master, after that I'll merge it :)

[lawrencegripper]

No worries, I've rebased this onto the current master now.