RFR: 364: The bots should not fetch tags by default

[Erik Helin]

Hi all,

please review this patch that makes the bots *not* fetch tags by default.
Fetching tags should be an explicit action, not something that happens as a side
effect of fetching commits.

Testing:
- `make test` on Linux x64

Thanks,
Erik

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Commit messages:
 - skara-364

Changes: https://git.openjdk.java.net/skara/pull/583/files
 Webrev: https://webrevs.openjdk.java.net/skara/583/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-364
  Stats: 52 lines in 15 files changed: 28 ins; 0 del; 24 mod
  Patch: https://git.openjdk.java.net/skara/pull/583.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/583/head:pull/583

PR: https://git.openjdk.java.net/skara/pull/583