Add role::statsd; provision on tungsten; grant self access

tungsten is the eqiad host slotted to replace professor.pmtpa as the primary
graphite and statsd host. This patch declares tungsten in site.pp and applies a
new 'role::statsd' to it. It also grants me access with sudo.

RT: 5871
Change-Id: I3a28d36cdbae90f5a6c4276dc445a94d56da6f52
Merge "Add role::statsd; provision on tungsten; grant self access" into production