Idle time, connection TTL and other features

[droscy]

Hello, I started receiving invalid data from inverter after a firmware upgrade and so I added to modbus-proxy some features in order to diagnose and bypass inconsistent reading.

These are the new parameters I've added:

• idle_time: how many seconds to wait before closing an idle connection to the modbus device
• connection_ttl: max duration of a connection, in seconds, to the modbus device
• reconnect_delay: how many seconds to wait before establishing a new connection to the modbus device after an error
• request_delay: how many seconds to wait between two requests

[tiagocoutinho]

Looks good.
Sorry for the late feedback.
I would feel more comfortable if the PR included tests. Would you mind adding a few?

[droscy]

I would feel more comfortable if the PR included tests. Would you mind adding a few?

Sure, as soon as I can study your test framework I'll add some test cases.

[droscy]

I've added some tests for the new parameters. All these tests are based on the asyncio.sleep() function to emulate the passing of time, so there is a remote chance of failure because the sleep() is not 100% time-accurate.

I've also added myself among contributors; other contributors are present in git history but I left the decision to you to add them to the readme file.