input: Write a python function to create a neural network model using Keras with an input shape of (128,) and an output layer with 5 neurons using softmax activation.
  assert isinstance(create_keras_model().layers[0], keras.layers.InputLayer)
  assert isinstance(create_keras_model().layers[-1], keras.layers.Dense)
  assert create_keras_model().layers[-1].output_shape == (None, 5)
output: def create_keras_model():
      from tensorflow.keras.models import Sequential
      from tensorflow.keras.layers import Dense, InputLayer
  
      model = Sequential()
      model.add(InputLayer(input_shape=(128,)))
      model.add(Dense(5, activation='softmax'))
      
      return model