Include jacoco and coveralls plugins in pom
Improve failure policy instantiation testing
Verify non-KafkaMessageId acks/fails have no effect on the buffer
Include test coverage report submission to coveralls.io
Include test coverage badge in README.md, clarify status badges are for development branch
Verify that illegal queue state will throw exception in nextTuple()
Mimic ConsumerIterator behaviour more closely in mock

ConsumerIterator will always return true for hasNext, but throw
CosumerTimeoutException when messages are not available fast enough.
Test simple declarative methods in KafkaSpout
Default empty consumer group config to default value
Test configuration of consumer group id
Merge pull request #6 from HolmesNL/features/coveralls

Enable coveralls integration