text: Title: Add Q-Q plot to the yellowbrick.regressor.residuals class
  Body: You already have a histogram feature for the `ResidulaPlot` method.
  It will be immensely helpful to add a standard normality check method to the parent `yellowbrick.regressor.residuals` class like Q-Q plot.
  
  Your functional interface is gearing up to be similar to statistical languages like **R** where you can throw the fitted model inside a function to generate more insight - mostly a visualization or a statistical score.
  
  [Q-Q plot](https://en.wikipedia.org/wiki/Q%E2%80%93Q_plot) ability will be one of such basic statistical insights that can add value.
  