Revert throwing exception on missing directive wiring (ExpediaGroup#251)

There are use cases when directives could be just informational (e.g. @deprecated). Instead of defining no-op directive wiring we should just ignore directives without wiring.

Explicit support for deprecated directive in the schema (ExpediaGroup…

…#247)

* Explicit support for deprecated directive in the schema

* custom SDL printer

* customize schema print extension, fix unit tests and detekt

* add printer tests

* revert changes to GraphQLName

example: add another nested example (ExpediaGroup#239)

Update to latest kotlin and fix incorrect jackson version in the exam…

…ple (ExpediaGroup#233)

Typo, "subsciptions" -> "subscriptions" (ExpediaGroup#227)

fix: abstract classes as input are invalid (ExpediaGroup#223)

* fix: abstract classes as input are invalid

* update unit tests for detekt

fix: abstract classes should generate interface (ExpediaGroup#221)

Fixes: ExpediaGroup#220

feat: subscriptions (ExpediaGroup#215)

* feat: subscriptions

* rename extension method

build: 0.2.13-SNAPSHOT (Travis Build 721) (ExpediaGroup#208)

Function builder ignores parameters annotated with GraphQLIgnore (Exp…

…ediaGroup#207)