memcached_exporter-2019032719

Add monitor multiple instances per exporter

--memcached.address="127.0.0.1:11211,127.0.0.1:11212"

# HELP memcached_uptime_seconds Number of seconds since the server started.
# TYPE memcached_uptime_seconds counter
memcached_uptime_seconds{server="127.0.0.1:11211"} 1355
memcached_uptime_seconds{server="127.0.0.1:11212"} 1352
# HELP memcached_version The version of this memcached server.
# TYPE memcached_version gauge
memcached_version{server="127.0.0.1:11211",version="1.5.12"} 1
memcached_version{server="127.0.0.1:11212",version="1.5.12"} 1
# HELP memcached_written_bytes_total Total number of bytes sent by this server to network.
# TYPE memcached_written_bytes_total counter
memcached_written_bytes_total{server="127.0.0.1:11211"} 139454
memcached_written_bytes_total{server="127.0.0.1:11212"} 141395