add ability for AgentCheck instances to collect service check data
update the collector to collect service check data from agent checks
Merge pull request #910 from DataDog/service-checks

adding service checks api
Upgrade to cassandra 2.0.7 to fix travis tests
rename service_name to check_name

Services could have multiple checks
Merge remote-tracking branch 'origin/service-checks'
allow for float timestamps in service checks
fix service check test
add generated ids to service checks
allow service_check host_name be overridable, defaulting to agent host name
Merge branch 'service-checks'
update service check docstring
rename check_id to check_run_id for clarify
Merge branch 'service-checks'
Support redis check on Windows
Fix the way we add redis in the package
Bump version to 4.2.2
Merge branch 'redis_windows'
Update changelog for 4.2.2
fix hostname vs host_name