Use mongoid-rspec 1.5.5 with capybara 1.1.2 by aliasing a conflicting `have_field` rspec matcher

01-spec_helper.rb

def fix_capybara_mongoid_matcher_conflict
  Capybara::RSpecMatchers.module_eval do
    alias :have_input :have_field
  end
end

RSpec.configure do |config|
  fix_capybara_mongoid_matcher_conflict
  config.include Mongoid::Matchers
end

02-spec.rb

# Unit test
it { should have_field('email') }

# Integration test
it { should have_input('user_email') }