Remove runtime dependency on KafkaProducer.
Catch NPE in MetricsManager init.
Allow initialization of MetricsManager without a hard-coded path.
Add App base class for managing HealthChecks.
Consumers should not touch MetricsManager. Only SubmissionHandler needs to.
Make MetricsManager non-static.
Use App to prepare HealthChecks, not MetricsManager.
Allow selection of MetricsManager when instantiating Bagheera server.
Merge pull request #7 from mozilla-metrics/rnewman/for-test-2

More automation changes