Rely on dropwizard-protobuf so we can use the ProtocolBufferMediaType
Re-generate protobuf with protoc v2.6.0
Depend on dropwizard-client and don't create a shaded jar
Upgrade dependencies

- maven-compiler-plugin from 3.1 to 3.2
- maven-surefire-plugin from 2.17 to 2.18
- maven-failsafe-plugin from 2.17 to 2.18
- maven-source-plugin from 2.3 to 2.4
- maven-resources-plugin from 2.6 to 2.7
- maven-javadoc-plugin from 2.9.1 to 2.10.1
- maven-release-plugin from 2.5 to 2.5.1
- coveralls-maven-plugin from 2.2.0 to 3.0.1
Upgrade newrelic-api from 3.11.0 to 3.12.0
Upgrade dropwizard-discovery from 0.7.1-2 to 0.7.1-5