mesos https support

http scheme is hardcoded on https://github.com/cloudflare/complainer/blob/master/mesos/cluster.go#L148 and https://github.com/cloudflare/complainer/blob/master/mesos/cluster.go#L162

Complainer should instead extract and use the scheme from the first `--masters`, or add an option to enable https.

Open mesos/cluster.go around lines 148 and 162, then trace how the first --masters value is parsed. Determine whether the implementation should use that URL scheme or expose an HTTPS option; done means Mesos masters using https no longer receive hardcoded http requests.

Written by the indexing model from the issue text.