Update release notes for 0.3.7

10 jobs for master in 30 minutes and 56 seconds (queued for 1 second)
Name Stage Failure
failed
fedora-tsan-test Test
[1556515655731] INFO: Closing state machine '/tmp/quarkdb-tests/server4-23460/current/state-machine'
[1556515655735] INFO: Closing raft journal '/tmp/quarkdb-tests/server4-23460/current/raft-journal'
[==========] 273 tests from 89 test cases ran. (84695 ms total)
[ PASSED ] 272 tests.
[ FAILED ] 1 test, listed below:
[ FAILED ] Raft_e2e.replication_with_trimmed_journal

1 FAILED TEST
ERROR: Job failed: exit code 1