Proposal: Reporter support

[TwitchBronBron]

This describes custom reporter support in rooibos.

1. Deprecate reporter in favor of reporters. Internally copy reporter value into reporters so it's backwards compatible. reporters will be an array of reporter factory functions (or class name).

bsconfig.json

{
    "rooibos": {
        "reporters": [
           "JUnit",
          "MyNamespace_MyCustomReporter",
           "happyReporter"
        ]
    }
}

2. The rooibos runtime will now support multiple reporters. Each string name in the reporters list will be the name of a function that is a reporter factory (which also will support class names too since those are technically factories anyway). These reporters are created ONCE, at the start of the entire test run. These reporters much confirm to the following structure: Each method is optional.

• onBegin - called at the very start of the testing process.
• beforeSuite - called before the first test in each @suite
• beforeDescribe - called before the first test in each @describe block
• beforeIt - called before each @it() test. If the test is parameterized, will be called once for each parameterized combo. To help better reporting with parameterized tests, will include some form of isParameterized and index so you can report a header at the start of a parameterized @it group.
• afterIt - called after each @it. Same rules as beforeIt
• afterDescribe - called after the final test in this @describe block finishes
• afterSuite - called after the final test in this @suite finishes
• onEnd - called when the entire testing process is finished

Here's an example reporter factory:

```brighterscript
function happyReporter()
    return {
        onBegin: function(event)
            print "About to run your first rooibos test!"
        end function
        beforeSuite: function(event)
            print "before run suite " event.suite.name
        end function
        beforeDescribe: function(event)
            print "before run describe " event.describe.name
        end function
        beforeIt: function(event)
            print "before run it " event.it.name
        end function
        afterIt: function(event)
            print "after run it " event.it.name
        end function
        afterDescribe: function(event)
            print "after run describe " event.describe.name
        end function
        afterSuite: function(event)
            print "before run suite " event.suite.name
        end function
        onEnd: function(event)
            print "Yay, tests are done"
        end function
    }
end function

3. The internals of rooibos will need to revise how reporting is done. We haven't flushed out the specific interfaces for the callback event structures.

[luis-soares-sky]

Just so it isn't forgotten, these reporters will need to be supported in node tests as well.

Unless you're thinking of revamping how node tests report their results (as I think they're self-reporting right now), the easiest way I can think of is to have an option to add custom .bs imports for the rooibos-generated nodes.