Support generation of DML script using Keras2DML and Caffe2DML

from keras.applications.vgg16 import VGG16

keras_model = VGG16(weights="imagenet", pooling="max") 

from systemml.mllearn import Keras2DML

sysml_model = Keras2DML(spark, keras_model, input_shape=(3,224,224), weights='weights_dir')

sysml_model.set(test_algo='batch', train_algo='minibatch')

print(sysml_model.get_training_script())

print(sysml_model.get_prediction_script())