Update cucumber

cucumber 4.0.0 is not aware of breaking changes in diff-lcs 1.4.3, so
excluding it

cucumber 3.2 would run on Ruby 2.2, 2.3 and 2.4

Sibling PRs:
 - rspec/rspec-core#2877
 - rspec/rspec-mocks#1439
 - rspec/rspec-expectations#1320

Author: pirj

cucumber.yml

@@ -1,3 +1,3 @@
-default: --require features --format progress --tags ~@wip
-pretty:  --require features --format pretty   --tags ~@wip
+default: --require features --format progress --tags 'not @wip'
+pretty:  --require features --format pretty   --tags 'not @wip'
 wip:     --require features --tags @wip

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', '~> 1.3.5'
+  s.add_development_dependency 'cucumber', '>= 3.2', '!= 4.0.0', '< 8.0.0'
 end