Update build and test system, add package deployment

• update gradle file
• publish gradle package
• use tests from gradle dependencies

src/main/jastadd/backend/Serializer.jadd

@@ -592,7 +592,7 @@ aspect Serializer {
     sb.append(ind(3) + "if (map.keySet().contains(unique$Id())) {\n");
     sb.append(ind(4) + "throw new RuntimeException(new SerializationException(\"UID \" + this.unique$Id() + \" is assigned to both \" + this.getClass().getSimpleName() + \":\" + this.hashCode() + \" and \" + map.get(unique$Id()).getClass().getSimpleName() + \":\" + map.get(unique$Id()).hashCode()));\n");
     sb.append(ind(3) + "} else {\n");
-    sb.append(ind(4) + "map.put(this.unique$Id, new java.lang.ref.WeakReference(this));\n");
+    sb.append(ind(4) + "map.put(this.unique$Id(), new java.lang.ref.WeakReference(this));\n");
     sb.append(ind(3) + "}\n");
     sb.append(ind(2) + "}\n");
     sb.append(ind(2) + "for (ASTNode child : astChildren()) {\n");