Written the unit testcases for GTransport. Though these are not unit
tests per se, wanted to test the GET and POST functionality and they
work. Will keep on adding more tests later.

Signed-off-by: Sateesh Kavuri <sateesh@mobilitas.co>
Fixed some issues with GTransport while unit testing. Started working on
the client plugin class. Next target is to complete the slow-sync flow
of pulling contacts from server to client

Signed-off-by: Sateesh Kavuri <sateesh@mobilitas.co>