Added initial example web API client and tests.

Summary: Added a simple OAuth1.0a client that can fetch a list of topics and tests containing a self-contained Jersey Oauth1.0a server to test authentication.

Test Plan: https://travis-ci.org/MediaMiser/rest-client/builds/23533849

Reviewers: samer.albuhaisi, yan.shi, david.nadeau, fan.zhao

Differential Revision: http://phabricator.mediamiser.internal/D1030