title: GridSearchCV progress in Jupiter Notebook
body: <p>Is it possible to see the progress of GridSearchCV in a Jupyter Notebook? I'm running this script in python:</p>
  
  <pre><code>param_grid = {'learning_rate': [0.05, 0.10, 0.15, 0.20, 0.25, 0.30] ,
  'max_depth'        : [3, 4, 5, 6, 8, 10, 12, 15],
  'min_child_weight' : [1, 3, 5, 7],
  'gamma'            : [0.0, 0.1, 0.2 , 0.3, 0.4],
  'colsample_bytree' : [0.3, 0.4, 0.5 , 0.7],
  'verbose'          : [100] }
  
  xgboost_reg = XGBRegressor()
  grid_search = GridSearchCV(xgboost_reg, param_grid, cv=5, scoring='neg_mean_squared_error', return_train_score=True)
  grid_search.fit(my_data, my_labels, verbose=False)
  </code></pre>
  
  <p>I can see only some warnings in the output of the cell.</p>