Add Gemfile which is for bundler

cosmo0920 · cosmo0920 · commit 19cf19651709 · 2017-09-19T13:52:08.000+09:00
diff --git a/Gemfile b/Gemfile
@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+source "https://rubygems.org"
+
+gemspec

-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +# frozen_string_literal: true
 +source "https://rubygems.org"
++
 +gemspec