* master: (254 commits)
  Reduce the maximum amount of argument to pylint.
  [forwarder] stop flushing after 10s
  [etcd] Report errors connecting to etcd endpoint (#3007)
  Postfix check should pass raise_on_empty_output=False
  [status] Silence requests exception
  [psutil] Only set `psutil.PROCFS_PATH` once in the collector (#3013)
  [ci] fix check name detection of test files (#3021)
  [ci][rabbitmq] Increase wait timeout (#3022)
  [core] SpooledTemporaryFile for subprocess output (#3002)
  [collector] isolate system checks (#3001)
  [ci] Fix Travis jobs timing out (#3017)
  [mongo] Use db.current_op instead of manually querying (#3016)
  [ci] fix bad citizens detection (#3020)
  [ci] add debug logs (#3019)
  [mongo] use `currentOp` for mongodb 3.2+
  Use proxy for API key check in info page (#3012)
  [mongo] Add MongoDB 3.2 support
  [mongo] Add MongoDB 3.2 to travis-ci config
  [packaging] 5.11.0 nightlies (#3009)
  [core] hard-deprecate start/stop/restart/status (#3004)
  ...