Fixed reference resolution (#354)

Author: valb3r

multiapi-engine/src/main/java/com/sngular/api/generator/plugin/asyncapi/util/ReferenceProcessor.java

@@ -51,7 +51,7 @@ public void processReference(
     if (!totalSchemas.containsKey(calculatedKey) && !alreadyProcessed.contains(calculatedKey)) {
       alreadyProcessed.add(calculatedKey);
       try {
-        if (referenceLink.toLowerCase().contains(YML) || referenceLink.toLowerCase().contains(JSON)) {
+        if (referenceLink.toLowerCase().contains(YML) || referenceLink.toLowerCase().contains(YAML) || referenceLink.toLowerCase().contains(JSON)) {
           component = solveRef(ymlParent, path, referenceLink, totalSchemas);
         } else {
           if (referenceLink.toLowerCase().contains(AVSC)) {