Update pymodbus to 1.4.0

[pyup-bot]

There's a new version of pymodbus available.
You are currently using 1.3.2. I have updated it to 1.4.0

These links might come in handy: PyPI | Changelog | Repo | Docs

Changelog

1.4.0

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• Bug fix Modbus TCP client reading incomplete data
• Check for slave unit id before processing the request for serial clients
• Bug fix serial servers with Modbus Binary Framer
• Bug fix header size for ModbusBinaryFramer
• Bug fix payload decoder with endian Little
• Payload builder and decoder can now deal with the wordorder as well of 32/64 bit data.
• Support Database slave contexts (SqlStore and RedisStore)
• Custom handlers could be passed to Modbus TCP servers
• Asynchronous Server could now be stopped when running on a seperate thread (StopServer)
• Signal handlers on Asyncronous servers are now handled based on current thread
• Registers in Database datastore could now be read from remote clients
• Fix examples in contrib (message_parser.py/message_generator.py/remote_server_context)
• Add new example for SqlStore and RedisStore (db store slave context)
• Fix minor comaptibility issues with utilities.
• Update test requirements
• Update/Add new unit tests
• Move twisted requirements to extra so that it is not installed by default on pymodbus installtion

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[pyup-bot]

Closing this in favor of #123