The `bundler 2.1.4` and `ruby 2.7`
do require a new spring version
due to how gems are being resolved.

Prevents output like this:

    Array values in the parameter are deprecated. Please use a String or nil.
    An Array was passed in from bin/rspec:3:in `load'

Now possible to run:
`bin/rails`
`bin/rspec`
`bin/spinach`
`bin/rake`