Add Send method to FakeMetricSender
Add Send method to FakeMetricSender

deaagent tests were failing due to the FMS not matching the expected
interface.

[#126514527]

Signed-off-by: Sam Nelson <7f9518b0fc80ae8ec9b933cc7d9f449459d97036@pivotal.io>

cloudfoundry/dropsonde,cloudfoundry/dropsonde