ansible: release v1.0.3 (pingcap#429)

dm-ansible: release v1.0.2 (pingcap#343)

checker: keep the original database error in the error message (pingc…

…ap#276)

conn: add max idle conn config (pingcap#280) (pingcap#281)

ansible: release v1.0.0 (pingcap#272)

*: add release notes for 1.0 RC.1 (pingcap#192)

tag used to release v1.0.0-alpha