RFR: Use a bare repo for notifier

[Robin Westberg]

The local repo needs to be bare to allow fetching refs

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Commit messages:
 - Use a bare repo for notifier

Changes: https://git.openjdk.java.net/skara/pull/908/files
 Webrev: https://webrevs.openjdk.java.net/?repo=skara&pr=908&range=00
  Stats: 16 lines in 2 files changed: 5 ins; 0 del; 11 mod
  Patch: https://git.openjdk.java.net/skara/pull/908.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/908/head:pull/908

PR: https://git.openjdk.java.net/skara/pull/908