Add agent_checks to metadata sent
Add agent checks errors to metadata
send checks for all instances
Add source_type_name to checks, default is file name
override checks source_type_name when needed
Update system checks source_type_name + fix typo
resolve merging conflicts
make checks fail
Remove useless SOURCE_TYPE_ID
Update variable name
Revert "make checks fail"

This reverts commit e14b0264517b8d7944a2c59826824debff5e0607.
Fix typo
Merge pull request #922 from DataDog/tristan/agent-checks-ui

Tristan/agent checks ui