v0.2.2

• GraphiQL v0.11.11 @ #35
• README improvements @ #36, #41, #49
• Playground support @ #37
• Config.RootObjectFn support @ #42
• CircleCi @ #48
• Config.ResultCallbackFn support @ #50
• Code clean-up @ https://github.com/graphql-go/handler/pull/52/files