MXNet Container Endpoint Deployment Failed

In notebook: https://github.com/awslabs/amazon-sagemaker-examples/blob/master/reinforcement_learning/rl_hvac_coach_energyplus/rl_hvac_coach_energyplus.ipynb

Model deployment is unsuccessful. Testing the model endpoint with

`action, action_mean, action_std = predictor.predict(np.array([0., 0., 2.,]))`

Returns:

`AttributeError: 'NoneType' object has no attribute 'predict'`

To reproduce error:

1. Launch SM Notebook instance
2. Clone https://github.com/awslabs/amazon-sagemaker-examples.git
3. Open https://github.com/awslabs/amazon-sagemaker-examples/blob/master/reinforcement_learning/rl_hvac_coach_energyplus/rl_hvac_coach_energyplus.ipynb
4. Click "Cell" -> "Run All"

Start with reinforcement_learning/rl_hvac_coach_energyplus/rl_hvac_coach_energyplus.ipynb and run the notebook through the predictor call shown in the issue. Trace why model deployment leaves predictor as None; done means the notebook deploys the model successfully and the sample prediction returns values instead of raising AttributeError.

Written by the indexing model from the issue text.