LOPY to ERA-LORA board communication

[jmarcelino]

@pkilcoyne

You also need to match:

1. the coding rate e.g. coding_rate=LoRa.CODING_4_5
2. the Sync Keyword (the public=True means 0x34, public=False means 0x12)
3. Preamble length (the Lopy default is 8, set by preamble=8)
4. Make sure the IQ matches the inversion setting (for transmit and receive, set by default to tx_iq=False, rx_iq=False )