v0.13.1

Main changes are:

1. Ocean3d major refactoring

AQUA core complete list:

• Fixer delete option accepts non-lists (#1687)
• Ansi color 8-bit fix for logger (#1671)
• Hotfix for unmatched string in catgen (#1672)
• Test for aqua-analysis.py (#1664)
• Fix in the catgen now correctly generating an automatic description if not provided (#1662)

AQUA diagnostics complete list:

• Diagnostic core: added a Diagnostic class to be inherited by all diagnostics (#1681)
• Timeseries: hotfix of problems with the catalog usage in output saving (#1669)
• Tropical Rainfall: Update of the precomputed histograms paths for lumi and MN5 (#1661)
• Ocean3d: Trend is calculating using polyfit. Restructed the mixed layer depth function. (#1651)