add bundler configuration helper for tork-master(1)

This lets you run Tork inside any application that uses Bundler without
having to first add Tork to its `Gemfile` and then `bundle install` it.
In fact, installing the Tork gem _outside_ of the bundle is sufficient.

Try it: go into a bundled application and call `tork` to run its tests!
Merge branch 'other'
Merge branch 'patch'
Merge branch 'minor'
Version 19.8.0 (2014-06-23)