Use a branch of scala with a patch to ./pull-binary-libs

Trying to avoid:

    [info]
    [info] boot:
    [info]      [echo] Updating bootstrap libs.  (To do this by hand, run ./pull-binary-libs.sh)
    [info]      [exec] find: `/localhome/jenkinsdbuild/workspace/Community/lib': No such file or directory
    [info]      [exec] find: `/localhome/jenkinsdbuild/workspace/Community/test/files': No such file or directory
    [info]      [exec] find: `/localhome/jenkinsdbuild/workspace/Community/tools': No such file or directory
    [info]     [touch] Creating /localhome/jenkinsdbuild/workspace/Community 2.11.x retronym/dbuild-0.7.1-M1/target