Add scheduled task "cron" support

[tmaiaroto]

Add scheduled task "cron" support

[tmaiaroto]

Create a tasks folder within app (where aegis command runs alongside source code). Add JSON files with the following contents:

{
    "schedule": "rate(1 hour)",
    "input": {
        "_taskName": "test",
        "foo": "bar"
    }
}

Enjoy. Schedule updates on each deploy as it gets changed. _taskName is conventional and allows Tasker handlers to handle specific tasks by name. Tasker like Router also has a "fall through" handler that catches everything. At that point, the catch all handler function could look at the input map and do whatever it needs to do. So tasks by name are completely optional.

Task handlers will get a map[string]interface{} that is this input key value from each of the JSON files within the tasks directory.