feat(grafana,telegraf): Pull metric data from nsq via telegraf

[jchauncey]

This PR updates several parts of the monitoring stack to support our move to NSQ. It is in progress for now since we are waiting for telegraf to merge my PR - influxdata/telegraf#1369

[deis-bot]

@krancour and @sstarcher are potential reviewers of this pull request based on my analysis of git blame information. Thanks @jchauncey!

[arschles]

@jchauncey looks like you're downloading the telegraf deb and then installing telegraf in the Dockerfile at telegraf/rootfs/Dockerfile, but you also have checked in the telegraf binary. From the description of this PR, sounds like you're gonna download the telegraf binary going forward (either from the official releases or our custom build from our own object storage), so can we get rid of the checked-in binary?

[arschles]

nit: worth making the prefixes for all these env vars NSQD_?

[jchauncey]

I did it so it matches the plugin name. Which is nsq_consumer

[arschles]

@jchauncey the json diffs are a bit hard to parse, but the changed files themselves look ok. my nitpick is not blocking for this PR. Also, thanks for removing the telegraf binary.

Code LGTM

[jchauncey]

Yeah the json diffs suck. easy way to test it is to build and push the image and check the graphs out