RFR: 170: Implement setTitle for GitHub pull requests

[Robin Westberg]

Hi all,

Please review this small change that implements the setTitle PullRequest API for GitHub.

Best regards,
Robin

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Commits:
 - ccde4614: Implement setTitle

Changes: https://git.openjdk.java.net/skara/pull/266/files
 Webrev: https://webrevs.openjdk.java.net/skara/266/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/SKARA-170
  Stats: 3 lines in 1 file changed: 2 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/266.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/266/head:pull/266

PR: https://git.openjdk.java.net/skara/pull/266