Bump version graphql-java from 17.2 to 20.4

Author: anatol-sialitski

build.gradle

@@ -54,7 +54,7 @@ gradle.projectsEvaluated {
 
 dependencies {
     compile 'javax.validation:validation-api:1.1.0.Final'
-    compile 'com.graphql-java:graphql-java:20.3'
+    compile 'com.graphql-java:graphql-java:20.4'
     compile 'com.graphql-java:graphql-java-extended-scalars:20.2'
     compile 'javax.xml.bind:jaxb-api:2.3.1'