git-ubuntu clone should setup remote-tracking branches

git-ubuntu currently doesn't setup remote tracking branches when cloning:

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$ git-ubuntu clone hello
$ cd hello
$ git branch
* ubuntu/devel
$ git pull
There is no tracking information for the current branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>

If you wish to set tracking information for this branch you can do so with:

    git branch --set-upstream-to=<remote>/<branch> ubuntu/devel
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If manually configured it works fine:

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$ git branch --set-upstream-to=pkg/ubuntu/devel ubuntu/devel
branch 'ubuntu/devel' set up to track 'pkg/ubuntu/devel'.
$ git pull
Already up to date.
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I believe this should be the default, as it's sometimes useful to update branches in locally cloned branches when the archive moves.