Development updates (#552)

- Update appraisal now that the issue blocking the update is fixed.
- Relax the version range of aruba so the latest version can be used.
- Ignore .ruby-gemset for developers who use gemsets.

.gitignore

@@ -12,3 +12,4 @@ Gemfile.lock
 spec/examples.txt
 .idea
 .ruby-version
+.ruby-gemset

cucumber-rails.gemspec

@@ -31,8 +31,8 @@ Gem::Specification.new do |s|
 
   # Main development dependencies
   s.add_development_dependency('ammeter', '>= 1.1.4')
-  s.add_development_dependency('appraisal', '< 2.4') # See: https://github.com/thoughtbot/appraisal/issues/186
-  s.add_development_dependency('aruba', '~> 1.0')
+  s.add_development_dependency('appraisal', ['>= 2.4.1', '< 3'])
+  s.add_development_dependency('aruba', ['>= 1.0', '< 3'])
   s.add_development_dependency('bundler', '>= 1.17')
   s.add_development_dependency('database_cleaner', ['>= 1.8', '< 3.0'])
   s.add_development_dependency('rake', '>= 12.0')