Allow customizing attribute types (#282)

Author: fehnomenal

graphql-jpa-query-schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/GraphQLJpaSchemaBuilder.java

@@ -1038,7 +1038,7 @@ private GraphQLOutputType getAttributeOutputType(Attribute<?,?> attribute) {
     }
 
     @SuppressWarnings( "rawtypes" )
-    private GraphQLType getAttributeType(Attribute<?,?> attribute, boolean input) {
+    protected GraphQLType getAttributeType(Attribute<?,?> attribute, boolean input) {
 
         if (isBasic(attribute)) {
         	return getGraphQLTypeFromJavaType(attribute.getJavaType());
@@ -1474,4 +1474,4 @@ public RestrictedKeysProvider  getRestrictedKeysProvider() {
         return restrictedKeysProvider;
     }    
 
-}
+}