chainladder 0.8.13

The majority of this release was written by @kennethshsu and contains a first-time contribution from @genedan. Thank you!

Bug Fixes:

• #270 Fixed an issue affecting triangle instantiation
• #251 Fixed a bug in predict method that failed to honor development ages appropriatly
• #274 Addressed a pandas deprecation notice in the heatmap method.
• #258 Addressed silent error when predicting on a Triangle that is larger than the underlying model.
• #288 Addressed Bug in to_frame method
• #283 Addressed Bug in the calculation of LDFs in CaseOutstanding

Enhancements

• #293 Expanded functionality drop_high and drop_low arguments of Development estimator.
• #298, #299, #304, #305, #308 Documentation clean-up.