google-cloud-storage breaking changes

• 2.19.0 \u2192 3.0.0api

  The default checksum strategy for uploads has changed from None to "auto" ([#1383](https://github.com/googleapis/python-storage/issues/1383))

• 2.19.0 \u2192 3.0.0api

  Media operations now use the same retry backoff, timeout and custom predicate system as non-media operations, which may slightly impact default retry behavior ([#1385](https://github.com/googleapis/python-storage/issues/1385))

• 2.19.0 \u2192 3.0.0api

  The default checksum strategy for downloads has changed from "md5" to "auto" ([#1383](https://github.com/googleapis/python-storage/issues/1383))

• 2.19.0 \u2192 3.0.0removed

  Retries are now enabled by default for uploads, blob deletes and blob metadata updates ([#1400](https://github.com/googleapis/python-storage/issues/1400))

• 2.19.0 \u2192 3.0.0removed

  Blob.download_to_filename() now deletes the empty destination file on a 404 ([#1394](https://github.com/googleapis/python-storage/pull/1394))

• 2.19.0 \u2192 3.0.0removed

  Deprecated positional argument "num_retries" has been removed ([#1377](https://github.com/googleapis/python-storage/issues/1377))

• 2.19.0 \u2192 3.0.0removed

  Deprecated argument "text_mode" has been removed ([#1379](https://github.com/googleapis/python-storage/issues/1379))

• 1.44.0 \u2192 2.0.0removed

  Remove Python 2 support (#657)

Get this data programmatically \u2014 free, no authentication.