Feature/describe alias as system spec

[Andrew Havens]

Took a while for me to realize that I couldn't simply use "feature" as an alias to "describe" in my system specs because the type is hard-coded as :feature. Can we change this so that the type is inferred by the location instead of hard-coding as type: :feature? I'd like to be able to use the feature/scenario aliases in my system specs.

[Thomas Walpole]

`feature` is defined in capybara/lib/capybara/rspec/features.rb and is set up for people who are using RSpec feature specs.  If you're using system specs then you shouldn't be using `feature`.  However if you really want to use `feature` then you are  free to redefine it yourself.  Capybara won't be changing it's defaults because it would be a huge breaking change to a lot of people.