Wmul-rivendell

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Updated requirements.txt and install_requires to specify protobuf <= 3.19.4 when the python version is below 3.7.0 and
>= 3.19.0 when python version is above 3.7.0. protobuf dropped support for pythons lower than 3.7.0 when it released
version 3.20.0.

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Rebuilt requirements.txt to fix encoding and contents.

Update the cli help entries for load_current_log_line to more closely match what is in the README.

Fixed a bug in Rivendell Audio Importer. There was a bug in the way it called subprocess.run due to back-porting
behind Python 3.7. Python 3.6 does not have the subprocess.run: capture_output param.

Added full instructions to the README file and this CHANGELOG.

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Add requirements.txt and tests/requirements.txt

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The initial public release of the wmul_rivendell python module.