0.6.1

Changes in 0.6.1

All changes relate to maintenance of xcube's Python environment requirements in envrionment.yml:

• Removed explicit blas dependency (which required MKL as of blas =*.*=mkl)
  for better interoperability with existing environments.
• Removed restrictions of fsspec <=0.6.2 which was required due to
  Zarr #650. As #650 has been fixed,
  zarr=2.6.1 has been added as new requirement. (#360)