title: How to fix 'Object arrays cannot be loaded when allow_pickle=False' in the sketch_rnn algorithm
body: <p>I was running the sketch_rnn.ipynb on my jupyter notebook, upon loading the environment to load the trained dataset, it returned an error 'Object arrays cannot be loaded when allow_pickle=False'</p>
  
  <p>This is the code already used by google developers in developing the sketch_rnn algorithm that was even run in the google colab. In the past i have ran it myself on the google colab it worked but seems not to be working on my own jupyter notebook</p>
  
  <pre><code>from magenta.models.sketch_rnn.sketch_rnn_train import *
  from magenta.models.sketch_rnn.model import *
  from magenta.models.sketch_rnn.utils import *
  from magenta.models.sketch_rnn.rnn import * 
  
  model_params.batch_size = 1
  eval_model_params = sketch_rnn_model.copy_hparams(model_params)
  eval_model_params.use_input_dropout = 0
  eval_model_params.use_recurrent_dropout = 0
  eval_model_params.use_output_dropout = 0
  eval_model_params.is_training = 0
  sample_model_params = sketch_rnn_model.copy_hparams(eval_model_params)
  sample_model_params.max_seq_len = 1
  return [model_params, eval_model_params, sample_model_params]
  
  
  [train_set, valid_set, test_set, hps_model, eval_hps_model, 
  sample_hps_model] = load_env_compatible(data_dir, model_dir)
  </code></pre>
  
  <p>i expected the output to be </p>
  
  <pre><code>INFO:tensorflow:Downloading http://github.com/hardmaru/sketch-rnn- 
  datasets/raw/master/aaron_sheep/aaron_sheep.npz
  INFO:tensorflow:Loaded 7400/300/300 from aaron_sheep.npz
  INFO:tensorflow:Dataset combined: 8000 (7400/300/300), avg len 125
  INFO:tensorflow:model_params.max_seq_len 250.
  total images &lt;= max_seq_len is 7400
  total images &lt;= max_seq_len is 300
  total images &lt;= max_seq_len is 300
  INFO:tensorflow:normalizing_scale_factor 18.5198.
  </code></pre>
  
  <p>But it gave me</p>
  
  <pre><code>ValueError: Object arrays cannot be loaded when allow_pickle=False
  </code></pre>