Add rspec

imbecile.gemspec

@@ -26,4 +26,6 @@ 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_development_dependency "rspec", "~> 3.0"
 end