chainladder 0.5.5

Bug fixes

• resolves #62 Slicing cdf not working correctly
• resolves #61 groupby not consistent with pandas
• resolves #60 Development.drop_high and drop_low. drop_high and drop_low only drop one observation even if multiple observations match the criteria.
• resolves a bug in TailCurve where the fit_period slicer was not indexing properly
• Better support for the loc property of a Triangle.

Enhancements:

• Resolves #64 support pandas>=1.0.0. chainladder now works with pandas>=1.0.0
• New feature #63 fill values for undefined link ratio. fillna is a new parameter of the Development estimator
• New feature #58 Attachment age support in Tail methods. attachment_age is a new parameter of the TailCurve estimator.
• New feature #59 Add cl.concat functionality
• Added ability to perform arithmetic between a Triangle and an np.ndarray