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* CLI changes: error display in the progress bar is changed;
summary is printed after the executions
* more errors are retried when retrying is enabled, which allows for a higher
success rate
* fixed tcp connection pooling
* ``autoextract.aio.request_raw`` function allows to pass custom headers
to the API (not to remote websites)
* ``autoextract.aio.request_raw`` now allows to customize the retry
behavior, via ``retrying`` argument
* ``tenacity.RetryError`` is no longer raised by the library; concrete errors
are raised instead
* Python 3.9 support
* CI is moved from Travis to Github Actions