In our application at GitHub we were seeing a warning coming from
`assert_text` on the latest version and building the source from master.
Warning we were seeing:
```
/vendor/gems/2.7.1/ruby/2.7.0/gems/capybara-3.32.2/lib/capybara/minitest.rb:56: warning: Using the last argument as keyword parameters is deprecated; maybe ** should be added to the call
/vendor/gems/2.7.1/ruby/2.7.0/gems/capybara-3.32.2/lib/capybara/minitest.rb:56:in `assert_text'
```
The warning is only visible when `assert_text` is delegated from
minitest which is why I've updated the minitest_spec.rb file to include
an argument. I was unable to see or reproduce this warning in the assert
text test.
I don't really get why `ruby2_keywords` wasn't adequate for this change
but from my testing my changes work in Ruby 2.6 and 2.7 and fix the
warning in 2.7.
