Client release v1.8.2

• Workflows client no longer validates processing_level parameter values, as these have been enhanced to support new products
  and can only be validated server side.
• Catalog V2 bands now support the vendor_band_name field (known as name_vendor in Metadata/Catalog V1).
• Scenes support for masking in version 1.8.1 had some regressions which have been fixed. For this reason, version
  1.8.1 has been pulled from PyPI.
• New task groups now default to a maximum_concurrency value of 5, rather than the previous 500. This avoids the common
  problem of deploying a task group with newly developed code, and having it scale up and turning small problems into
  big problems! You may still set values as large as 500.
• The Tasks client now provides an update_group() method which can be used to update many properties of an existing
  task group, including but not limited to name, image, minimum_concurrency, and maximum_concurrency.
• Improved testing across several sub-packages.
• Various documentation fixes.