RFR: Implement HgRepository::amend

[Robin Westberg via github.com]

On Mon, 19 Aug 2019 12:49:38 GMT, Erik Duveblad via github.com <duke at openjdk.java.net> wrote:

> Hi all,
> 
> this patch implements the `HgRepository::amend` method. I also added a test that tests `amend` for both git and hg.
> 
> ## Testing
> - [x] `sh gradlew test` passes on
>   - [x] Linux
>   - [ ] Windows
>   - [ ] macOS
> 
> ----------------
> 
> Commits:
>  - 71734d51:	Implement HgRepository::amend
> 
> Pull request:
> https://git.openjdk.java.net/skara/pull/59
> 
> Webrev:
> https://webrevs.openjdk.java.net/skara/59/webrev.00
> 
> Patch:
> https://git.openjdk.java.net/skara/pull/59.diff
> 
> Fetch command:
> git fetch https://git.openjdk.java.net/skara pull/59/head:pull/59

This PR has been reviewed by Robin Westberg via github.com - changes are approved. Review comment:

PR: https://git.openjdk.java.net/skara/pull/59