Allow mutating existing definitions

This is a temporary fix. Should be fully fixed by #362.

Author: vojtapol

src/main/kotlin/graphql/kickstart/tools/TypeDefinitionFactory.kt

@@ -12,5 +12,5 @@ interface TypeDefinitionFactory {
      *
      * @return any new definitions that should be added
      */
-    fun create(existing: List<Definition<*>>): List<Definition<*>>
+    fun create(existing: MutableList<Definition<*>>): List<Definition<*>>
 }

src/main/kotlin/graphql/kickstart/tools/relay/RelayConnectionFactory.kt

@@ -5,7 +5,7 @@ import graphql.language.*
 
 class RelayConnectionFactory : TypeDefinitionFactory {
 
-    override fun create(existing: List<Definition<*>>): List<Definition<*>> {
+    override fun create(existing: MutableList<Definition<*>>): List<Definition<*>> {
         val definitions = mutableListOf<Definition<*>>()
         val definitionsByName = existing.filterIsInstance<TypeDefinition<*>>()
             .associateBy { it.name }