Better log level handling within micro

[tboerger]

Currently every log message from the micro internals are logged with the info level, we really need to respect the proper defined log level within our log wrapper package.

[tboerger]

If we log messages from github.com/micro/go-micro/util/log it should behave like the below:

log.Debug("Debug")
log.Error("Error")
log.Info("Info")
log.Warn("Warn")
log.Trace("Trace")
log.Fatal("Fatal")

2019-12-06T09:26:10+01:00 DBG Debug service=ocis
2019-12-06T09:26:10+01:00 ERR Error service=ocis
2019-12-06T09:26:10+01:00 INF Info service=ocis
2019-12-06T09:26:10+01:00 WRN Warn service=ocis
2019-12-06T09:26:10+01:00 DBG Trace service=ocis
2019-12-06T09:26:10+01:00 FTL Fatal service=ocis