Add Google test based tests.

Initial testing include an "id test", which really just a
template test at this point, and a temperature sensor test.

The google test code is included in this commit. It will
eventually be taken out and replaced with a pull from a google
external repo.

Change-Id: I591818a9c169f4654fc8d8f17cf648f227d72545

CMakeLists.txt

@@ -126,6 +126,7 @@ endforeach()
 add_subdirectory("server")
 add_subdirectory("client")
 add_subdirectory("tests/example")
+add_subdirectory("tests/rdc_tests")
 
 # TODO set(CPACK_DEBIAN_PACKAGE_HOMEPAGE <GITHUB URL> )
 set(CPACK_DEBIAN_PACKAGE_CONTROL_EXTRA