RaftConsensusITest.TestAddRemoveVoter sometimes fails in master branch

[tedyu]

Jira Link: DB-1144

Description

As of commit 2e54a0c317a649bdc25c324e3c2406cb85c001ad, RaftConsensusITest.TestAddRemoveVoter fails with:

[ts-1] W0122 15:45:41.168526 30904 heartbeater.cc:625] P df5a1aa47af3409a920d347f31193707: Failed to heartbeat to 127.0.0.1:35595: Network error (yb/util/net/socket.cc:540): Failed to send heartbeat: recvmsg error: Connection refused (system error 111) tries=12, num=1, masters=0x0000000002d3c3a8 -> [[127.0.0.1:35595]], code=Network error
Test failure stack trace:
../../src/yb/integration-tests/raft_consensus-itest.cc:2169:                                            @           0x457361  yb::tserver::RaftConsensusITest::AssertMajorityRequiredForElectionsAndWrites(std::unordered_map<string, yb::itest::TServerDetails*, std::hash<string >, std::equal_to<string >, std::allocator<std::pair<string const, yb::itest::TServerDetails*> > > const&, string const&)
../../src/yb/integration-tests/raft_consensus-itest.cc:1190:                                            @           0x45ab5f  yb::tserver::RaftConsensusITest::TestAddRemoveServer(yb::consensus::PeerMemberType)
../../src/yb/integration-tests/raft_consensus-itest.cc:2235:                                            @           0x477396  yb::tserver::RaftConsensusITest_TestAddRemoveVoter_Test::TestBody()
../../src/yb/integration-tests/raft_consensus-itest.cc:1190: Failure
Expected: AssertMajorityRequiredForElectionsAndWrites(active_tablet_servers, leader_uuid) doesn't generate new fatal failures in the current thread.
  Actual: it does.
Test failure stack trace:
../../src/yb/integration-tests/raft_consensus-itest.cc:1190:                                            @           0x45ac91  yb::tserver::RaftConsensusITest::TestAddRemoveServer(yb::consensus::PeerMemberType)
../../src/yb/integration-tests/raft_consensus-itest.cc:2235:                                            @           0x477396  yb::tserver::RaftConsensusITest_TestAddRemoveVoter_Test::TestBody()

[rthallamko3]

detective report

[rthallamko3]

Doesn't seem to be a problem anymore. Should have been fixed by some of the test stability fixes.