Added dependencies for weakref

Author: hsbt

weakref.gemspec

@@ -29,4 +29,6 @@ Gem::Specification.new do |spec|
   spec.bindir        = "exe"
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
+
+  spec.add_dependency "delegate"
 end