[Rev 01] RFR: notify: store resulting commit in PullRequestState

[Erik Helin]

> Hi all,
> 
> please review this patch that the resulting (integrated) commit from a PR in the `PullRequestState`. This data will be
> used in future patches for more easier handling of notifications. Note that all data in the `Storage` might not have
> the `"commit"` field. If that is the case, then the code will lazily populate the `"commit"` field.  Testing:
> - [x] `make test` on Linux x64
> 
> Thanks,
> Erik

Erik Helin has updated the pull request incrementally with one additional commit since the last revision:

  Configure integrator id

-------------

Changes:
  - all: https://git.openjdk.java.net/skara/pull/641/files
  - new: https://git.openjdk.java.net/skara/pull/641/files/4f70c74e..95e3f668

Webrevs:
 - full: https://webrevs.openjdk.java.net/skara/641/webrev.01
 - incr: https://webrevs.openjdk.java.net/skara/641/webrev.00-01

  Stats: 24 lines in 4 files changed: 16 ins; 0 del; 8 mod
  Patch: https://git.openjdk.java.net/skara/pull/641.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/641/head:pull/641

PR: https://git.openjdk.java.net/skara/pull/641