Includes features such as:
* `:Bundle`, which wraps `bundle`.
* An internalized version of `bundle open`: `:Bopen` (and `:Bsplit`,
* `'path'` and `'tags'` are automatically altered to include all gems
from your bundle. (Generate those tags with
* Highlight Bundler keywords in `Gemfile`.
* Support for `gf` in `Gemfile.lock`, plus syntax highlighting that
distinguishes between installed and missing gems.