Upgrade to Dropwizard 0.7.1

* Upgrade to Dropwizard 0.7.1.
* Upgrade newrelic-api from 3.5.0 to 3.72
* Upgrade httpclient from 4.3.3 to 4.3.4
* Upgrade metrics-core from 3.0.1 to 3.0.2
* Upgrade guava from 16.0.1 to 17.0