Every /health and /metrics request is logged

[Mortinke]

Bug reports:

Steps you follow to reproduce the error:
I deployed the docker image datareply/alertmanager-sns-forwarder:0.1 on our ECS-cluster without any parameters. Thus, no debug log should be activated

What did you expect to happen instead:
Only important information are logged like service started successfully, ARN prefix could not be detected, error while sending sns message, listening on:<port>, ....

What's your theory on why it isn't working:

gin.Default() add the Logger and Recovery middleware automaticly, see also issue #598. We should switch to gin.New() and add the gin.Logger() and gin.Recovery() manually, for example gin#using-middleware

[olgierdg]

Thanks, merged.