Add simple benchmark. [ci skip]

Author: marshall-lee

benchmark/simple.rb

@@ -0,0 +1,31 @@
+$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
+require 'grape'
+require 'benchmark'
+
+class API < Grape::API
+  prefix :api
+  version 'v1', using: :path
+  get '/' do
+    'hello'
+  end
+end
+
+options = {
+  method: 'GET'
+}
+
+env = Rack::MockRequest.env_for('/api/v1', options)
+
+10.times do |i|
+  env["HTTP_HEADER#{i}"] = '123'
+end
+
+iters = 5000
+
+Benchmark.bm do |bm|
+  bm.report('simple') do
+    iters.times do
+      API.call env
+    end
+  end
+end