Gemfile in chatwork-0.5.0 vs Gemfile in chatwork-0.6.0

@@ -1,4 +1,16 @@
-source 'https://rubygems.org'
+source "https://rubygems.org"
 
 # Specify your gem's dependencies in chatwork.gemspec
 gemspec
+
+if Gem::Version.create(RUBY_VERSION) < Gem::Version.create("2.3.0")
+  group :test do
+    gem "backport_dig", group: :development
+  end
+end
+
+if Gem::Version.create(RUBY_VERSION) < Gem::Version.create("2.2.2")
+  group :test do
+    gem "activesupport", "< 5.0.0", group: :development
+  end
+end