Merged PRs

• 1059: pass in-memory gc gen when we conjoin
  On the conjoin path, we're not passing "garbage collection generation" when we update the manifest. NomsBlockStore interprets this as the c
  onjoin having been preempted by and out-of-process write and blocks the write.
• 1052: Vinai/dolt commit author no config
  Add a bats test that models the following behavior.
  1. Unsets name and user.
  2. Makes a sql change
  3. Add a commit with --author