Adds test for proposer_proposed_count() in ProposerTest.
Adds test for proposer_proposed_count() in ProposerTest.

tudang/paxosudp,tudang/paxosudp,tyh20082000/libpaxos,tyh20082000/libpaxos,tudang/paxosudp,tudang/paxosudp,tyh20082000/libpaxos,tyh20082000/libpaxos,tudang/paxosudp,tudang/paxosudp