aostools v2.7

This is mainly a release to stay up to date given v2.6 was a while ago.

Main changes compared to v2.6:

• new function Regrid() uses xesmf for proper regridding 968f4c4
• new function Detrend() copied from xrft package (thanks!) e5a4bc4
• GlobalAvgXr() now also computes zonal mean by default 15c0aff
• renamed OceanIndex() to ClimateIndex() a092304

Bugfixes:

• SAM calculations have been corrected a2beebc
• inout.DefCompress() now ignores dimensions and integer arrays 8aa37bc, 8af6064
• AddColorbar() can now deal with single axes e75049c

Full Changelog: v2.6...v2.7