Removed the forkMe ribbon for mobile devices

Make sure these boxes are checked before your pull request (PR) is ready to be reviewed and merged. Thanks!

[ ] tests pass -- look for a green checkbox ✔️ a few minutes after opening your PR -- or run tests locally with rake test
[ ] code is in uniquely-named feature branch and has no merge conflicts
[ ] PR is descriptively titled
[ ] PR body includes fixes #0000-style reference to original issue #
[ ] ask @publiclab/reviewers for help, in a comment below

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We have a loose schedule of reviewing and pulling in changes every Tuesday and Friday, and publishing changes on Fridays.

Thanks!

publiclab / community-toolbox