Add support for forwarding statsd traffic.

JIRA: OPS-9042
Rafactoring.

This refactors the Server and Daemon modules.
"Server" is now "Aggregator".
Daemon now supports pluggable Statsd-handling modules.
Added some tests for the above.
Added pry for debugging and testing.
Added Guard for rspec, and a Guardfile.
Added tmp to .gitignore.

JIRA: OPS-9042
Merge pull request #3 from lookout/add_forwarder_support

Add support for forwarding statsd traffic.