Model_4 missing callback

[JPedro2]

'Earlystop' callback missing on model.fit() method:

model.fit(train_images, train_labels, epochs=20, validation_split=0.2, callbacks=[tensorboard])

should be:

model.fit(train_images, train_labels, epochs=20, validation_split=0.2, callbacks=[earlystop, tensorboard])