* Some improvment in mesos input plugin,
     Removing uneeded statistics prefix for task's metric,
     Adding framework id tags into each task's metric,
     Adding state (leader/follower) tags to master's metric,
     Make sure the slave's metrics are tags with slave

* typo, replacing cpus_total with elected to determine leader

* Remove remaining statistics_ from sample

* using timestamp from mesos as metric timestamp

* change mesos-tasks to mesos_tasks, measurement

* change measurement name in test

* Replace follower by standby