Release 1.0.7

* PCT-506: Losing sample every minute
* PCT-565: Skip MySQL metrics that take too long to collect
* PCT-764: Bad data file causes agent to stop sending but keep spooling data
* PCT-808: System info (PCT-809, PCT-810)
* PCT-863: Explain fails on multipart key_len
* Added X-Percona-Agent-Version header
* Built with github.com/go-sql-driver/mysql 0b000424e5