Same package as the one used for the paper "Evaluating climate models with the CLIVAR 2020 ENSO metrics package" published in BAMS (https://doi.org/10.1175/BAMS-D-19-0337.1) but now available in python3.

The released code is the same as in v1.1 but only with minor difference -- copyright info revised as owned by CLIVAR, for conda-forge release purpose.