docs: def tags(self):
          '''Display tag information for all samples in database'''
          tags = self.workbench.get_all_tags()
          if not tags:
              return
          tag_df = pd.DataFrame(tags)
          tag_df = self.vectorize(tag_df, 'tags')
          print '\n%sSamples in Database%s' % (color.LightPurple, color.Normal)
          self.top_corr(tag_df)