RTBKIT-527

This PR goes along @RTBKIT-527 and relies on https://github.com/datacratic/platform-deps/pull/1
It add support for Ubuntu 14.04(,x) LTS. 
Note that the following two tests have been modified i/o pass:
   
 * in soa/service/testing/runner_test.cc, de-activate test_runner_execute
 * most tests in soa/service/testing/http_client_test.cc are deactivated