Remove add_development_dependency from gem

Author: kojix2

Gemfile

@@ -4,3 +4,9 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in youplot.gemspec
 gemspec
+
+group :test do
+  gem 'rake'
+  gem 'simplecov'
+  gem 'test-unit'
+end

youplot.gemspec

@@ -19,10 +19,5 @@ Gem::Specification.new do |spec|
   spec.executables   = %w[uplot youplot]
   spec.require_paths = ['lib']
 
-  spec.add_runtime_dependency 'unicode_plot', '>= 0.0.5'
-  spec.add_development_dependency 'bundler'
-  spec.add_development_dependency 'rake'
-  spec.add_development_dependency 'rubocop'
-  spec.add_development_dependency 'simplecov'
-  spec.add_development_dependency 'test-unit'
+  spec.add_dependency 'unicode_plot', '>= 0.0.5'
 end