fix spelling error
Fix reference to wrong constant (Resque::Metrics, not Resque::Metric)
Merge pull request #3 from technicalpickles/fix-callback-example

Fix Forking Metrics example
Merge pull request #5 from technicalpickles/use-boxen-redis-if-present

Use boxen-provided redis if available
Merge pull request #2 from aschepis/patch-1

fix spelling error
Merge master