down.gemspec in down-3.0.0 vs down.gemspec in down-3.1.0

@@ -16,6 +16,7 @@
   spec.require_path = "lib"
 
   spec.add_development_dependency "minitest", "~> 5.8"
   spec.add_development_dependency "mocha"
   spec.add_development_dependency "http", "~> 2.1"
+  spec.add_development_dependency "docker-api"
 end