skinny
decode
compression and test cases
Merge branch 'skinnyhisto' into space-efficient

Conflicts:
	metrik-core/src/main/resources/application.conf
	metrik-stress/src/main/scala/com/despegar/metrik/stress/StressTest.scala
	project/Dependencies.scala
	src/main/scala/com/despegar/metrik/store/BucketStore.scala
skinnyHistogram + better serialization of summaries and counter buckets