Change channel cache to be BackgroundComputingValue instead of LoadingCache
Merge branch 'mbst-4019-ingest-pa-channel-data' into stage

Conflicts:
	src/main/java/org/atlasapi/persistence/media/channel/CachingChannelStore.java
Log error if duplicate alias found on channels, rather than throwing error.
Merge branch 'mbst-4019-ingest-pa-channel-data' into stage

Conflicts:
	src/main/java/org/atlasapi/persistence/media/channel/CachingChannelStore.java