Add BME280 sensor with example

[ba58smith]

Per a request from someone on Slack. Issue #96 .

[mairas]

Looks really good except for the two comments!

[KEGustafsson]

If BME280 device is not present or broken then SensESP startup fails and device is halted.
␛[0m(I) (check_status) Could not find a valid BME280 sensor. Check wiring, address, and sensor ID. ␛[0m(I) (check_status) SensorID is: 0x255 ␛[0m(I) (check_status) 0xFF: is a BMP180 or BMP085, or a bad address ␛[0m(I) (check_status) 0x56-0x58 is a BMP280 ␛[0m(I) (check_status) 0x60 is a BME280 ␛[0m(I) (check_status) 0x61 is a BME680 ␛[0m
Log reporting stops here.

Is this needed?
https://github.com/SignalK/SensESP/blob/master/src/sensors/bme280.cpp#L27

[mairas]

Is this needed?
https://github.com/SignalK/SensESP/blob/master/src/sensors/bme280.cpp#L27

I'd say that's harmful. Would be much better to catch the issue internally and just disable reading the values for the sensor and allow the rest of the program to continue.

Recommend opening an issue, though. Discussions in already merged PRs are quite difficult to find for most people. :-)

[KEGustafsson]

I'll do that and I'll copy your comment as an option to overcome the issue.
#151