text: Title: Label mismatch in horizontal contributions plot
  Body: in the horizontally oriented contribution plot the hover over labels are reversed, this is caused by the following lines in explainer_plots.py
  
  ```
  if orientation == 'horizontal':        
     cols = cols[::-1]        
     values = values[::-1]        
     contribs = contribs[::-1]        
     bases = bases[::-1]        
     fill_colors = fill_colors[::-1]        
     line_colors = line_colors[::-1]
  ```
  
  which misses
  
  `hover_text = hover_text[::-1]`
  
  ill open a pull request for the bug fix