v0.3.2.2: more bugfixes

Version 0.3.2.2:

index_dropdown=False now works for indexes not listed in set_index_list_func()
as long as it can be found by set_index_exists_func

New Features

• adds set_index_exists_func to add function that checks for index existing
  besides those listed by set_index_list_func()

Bug Fixes

• bug fix to make shap.KernelExplainer (used with explainer parametershap='kernel')
  work with RegressionExplainer
• bug fix when no explicit labels are passed with index selector
• component only update if explainer.index_exists(): no IndexNotFoundErrors anymore.
• fixed title for regression index selector labeled 'Custom' bug
• get_y() now returns .item() when necessary
• removed ticks from confusion matrix plot when no labels param passed
  (this bug got reintroduced in recent plotly release)

Improvements

• new helper function get_shap_row(index) to calculate or look up a single
  row of shap values.