Merge branch 'sg/ci-libsvn-perl'

To run tests for Git SVN, our scripts for CI used to install the git-svn package (in the hope that it would bring in the right dependencies). This has been updated to install the more direct dependency, namely, libsvn-perl. * sg/ci-libsvn-perl: ci: install 'libsvn-perl' instead of 'git-svn'