ztk.gemspec in ztk-1.4.1 vs ztk.gemspec in ztk-1.4.2

- old
+ new

@@ -44,6 +44,7 @@
   spec.add_development_dependency("pry")
   spec.add_development_dependency("rake")
   spec.add_development_dependency("rspec")
   spec.add_development_dependency("yard")
   spec.add_development_dependency("redcarpet")
+  spec.add_development_dependency("coveralls")
 end