First pass for service checks for ES, Postgres and Redis
Send tags with the service checks + code cleaning
Code cleaning
Add proper tags for service checks Postgres and Redis
Remove tags paramater in the get_connection function since service_tags do not include all tags
Add tests for service checks ES, Postgres and Redis
Add port and host as tags for ES service check + add tests for those tags
Do not parse the ES config url twice
Merge branch 'omnibus_bundling' into es-service-check

Conflicts:
	checks.d/redisdb.py
Small wording changes after Conor's comments
Merge pull request #999 from DataDog/es-service-check

Es service check