text: Title: Implement Detection Error Tradeoff Curves (DET) Visualizer
  Body: A community suggestion from reddit, implement a DET curve visualizer for model comparison.
  
  From [wikipedia](https://en.wikipedia.org/wiki/Detection_error_tradeoff):
  
  `A detection error tradeoff (DET) graph is a graphical plot of error rates for binary classification systems, plotting the false rejection rate vs. false acceptance rate.[1] The x- and y-axes are scaled non-linearly by their standard normal deviates (or just by logarithmic transformation), yielding tradeoff curves that are more linear than ROC curves, and use most of the image area to highlight the differences of importance in the critical operating region.`
  
  Aspiration Wikipedia image comparing multiple models:
  
  ![440px-example_of_det_curves](https://user-images.githubusercontent.com/2944777/40618185-9d284cd4-6245-11e8-994d-4edbcdd27344.png)
  
  
  Sample Code for plotting one model on a mpt object. Reference link below:
  
  ```
  from matplotlib import pyplot as plt
  def DETCurve(fps,fns):
      """
      Given false positive and false negative rates, produce a DET Curve.
      The false positive rate is assumed to be increasing while the false
      negative rate is assumed to be decreasing.
      """
      axis_min = min(fps[0],fns[-1])
      fig,ax = plt.subplots()
      plot(fps,fns)
      yscale('log')
      xscale('log')
      ticks_to_use = [0.001,0.002,0.005,0.01,0.02,0.05,0.1,0.2,0.5,1,2,5,10,20,50]
      ax.get_xaxis().set_major_formatter(matplotlib.ticker.ScalarFormatter())
      ax.get_yaxis().set_major_formatter(matplotlib.ticker.ScalarFormatter())
      ax.set_xticks(ticks_to_use)
      ax.set_yticks(ticks_to_use)
      axis([0.001,50,0.001,50])
  
  ```
  
  **Suggested Visualizer Interface**
  
  ```
  models = [LogisticRegression(), AnotherModel(), DifferentModel()]
  viz = DETCurve(models)
  viz.fit(X, y)
  viz.poof()
  ```
  
  
  
  
  Sample Code Reference Link
  https://jeremykarnowski.wordpress.com/2015/08/07/detection-error-tradeoff-det-curves/
  
  Source Reddit comment
  https://www.reddit.com/r/MachineLearning/comments/8mbif5/news_new_release_of_python_ml_visualization/dzpford/
  
  