Multiple dropped and egress metrics are being emitted.

[bradylove]

The adapter creates 3 separate dropped and 3 separate egress metrics that are identical, however they will have different values.

We should only have 1 dropped and 1 egress metric for the whole adapter.

See: https://github.com/cloudfoundry/scalable-syslog/blob/master/adapter/app/adapter.go#L224-L246

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/163066482

The labels on this github issue will be updated when the story is started.