Merge pull request graphql-go#448 from Fontinalis/extensions

Add extensions support

Merge pull request graphql-go#423 from graphql-go/formatted-error-pri…

…vate-original-error

errors: adds OriginalError support

Merge pull request graphql-go#376 from Quasilyte/quasilyte/assignOp

simplify assignments with <op>= syntax

Merge pull request graphql-go#278 from dvic/travis-race

Pass the '-race' flag to goveralls when running tests on TravisCI

Merge pull request graphql-go#268 from mrhenry/benchmarks

Add benchmarks

Merge pull request graphql-go#247 from christianpv/patch-1

Add dataloader to Third Party Libs in README.md

Merge pull request graphql-go#229 from graphql-go/atrniv/fix-cyclic-t…

…ypes

support for cyclic fields on defintion

Merge pull request graphql-go#195 from SnaphyLabs/master

Adding `AppendType` method to add Type to Schema object at runtime

Merge pull request graphql-go#216 from WindomZ/master

Examples: use '.Get("query")' instead of '["query"][0]'