ETROG-3513: Add DNN as new morphology model type

Author: juliencherry

model/src/main/java/com/basistech/rosette/apimodel/MorphologyModelType.java

@@ -21,6 +21,7 @@
  */
 public enum MorphologyModelType {
     DEFAULT,
+    DNN,
     PERCEPTRON,
     /**/;
 }