text: Title: Make quick methods primetime
  Body: After the visualizer audit we believe that the quick methods are ready to be made prime time. 
  
  Quick methods must:
  
  1. Have a function signature identical to the Visualizer constructor with additional data for fit/score
  2. Call `finalize()` and not `poof()`/`show()`
  3. Return the fitted visualizer instance
  4. Some visualizers must also insure that they call transform/fit_transform/score 
  
  For each visualizer found in the list below we must:
  
  - [x] refactor the quick method to the new API 
  - [x] document the quick method 
  - [x] ensure there is an associated test or tests for the quick method
  
  See #600 for more details on this issue
  
  - [x] class_prediction_error
  - [x] classification_report
  - [x] confusion_matrix
  - [x] precision_recall_curve
  - [x] roc_auc
  - [x] discrimination_threshold
  - [x] alphas
  - [x] cooks_distance
  - [x] prediction_error
  - [x] residuals_plot
  - [x] kelbow_visualizer
  - [x] intercluster_distance
  - [x] silhouette_visualizer
  - [x] balanced_binning_reference
  - [x] class_balance
  - [x] feature_correlation
  - [x] cv_scores
  - [x] learning_curve
  - [x] validation_curve
  - [ ] explained_variance_visualizer
  - [x] feature_importances
  - [x] rank1d
  - [x] rank2d
  - [x] rfecv
  - [x] joint_plot
  - [x] mainfold_embedding
  - [x] pca_decomposition
  - [x] parallel_coordinates
  - [x] radviz
  - [x] dispersion
  - [x] freqdist
  - [x] postag
  - [x] tsne
  - [x] umap
  - [ ] gridsearch_color_plot