improve readability of the honcho console logs in the dev environment

* colorize uwsgi and celery logs; DEBUG lines are green, WARN lines
  are yellow, ERROR lines (and tracebacks) are red
* pretty-print fact callback receiver JSON
* simplify the uwsgi log format so it's more legible

awx/main/tasks.py

@@ -225,7 +225,7 @@ def tower_periodic_scheduler(self):
     run_now = now()
     state = TowerScheduleState.get_solo()
     last_run = state.schedule_last_run
-    logger.debug("Last run was: %s", last_run)
+    logger.debug("Last scheduler run was: %s", last_run)
     state.schedule_last_run = run_now
     state.save()