Use the latest Cucumber

Originally:

> cucumber 3.2 would run on Ruby 2.2, 2.3 and 2.4

But Rails 6.1 and we only support Ruby 2.5+, so this is not needed.

Author: pirj

rspec-rails.gemspec

@@ -58,5 +58,5 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'ammeter',  '~> 1.1.5'
   s.add_development_dependency 'aruba',    '~> 0.14.12'
-  s.add_development_dependency 'cucumber', '>= 3.2', '!= 4.0.0', '< 8.0.0'
+  s.add_development_dependency 'cucumber', '~> 7.0'
 end