Move debugging gems to 'development' group

To allow them to be excluded in CI where they're not needed.

The name 'development' might make more sense than 'test'
because the code using all these gems _is_ used for running
tests.

qa/Gemfile

@@ -16,10 +16,10 @@ gem 'faker', '~> 1.6', '>= 1.6.6'
 gem 'knapsack', '~> 1.17'
 gem 'parallel_tests', '~> 2.29'
 gem 'rotp', '~> 3.1.0'
+gem 'timecop', '~> 0.9.1'
 
-group :test do
+group :development do
   gem 'pry-byebug', '~> 3.5.1', platform: :mri
   gem "ruby-debug-ide", "~> 0.7.0"
   gem "debase", "~> 0.2.4.1"
-  gem 'timecop', '~> 0.9.1'
 end