CarthageServerRole fails when run from an installed carthage-runner

[srak289]

copy_in_carthage setup task calls rsync_git_tree on os.path.dirname(carthage.__file__) which fails with

sh.ErrorReturnCode_128: 

  RAN: /usr/bin/git rev-parse --show-toplevel

  STDOUT:


  STDERR:
fatal: not a git repository (or any of the parent directories): .git