Modify esp32 socket.write to reflect socket core module api

[brentru]

Switching socket.write to socket.send to match the CircuitPython Socket API and the CPython Socket API.

Related library PRs:

• MiniMQTT
• Requests

Tested on: Adafruit CircuitPython 4.0.2 on 2019-06-27; Adafruit PyPortal with samd51j20

Tests ran:
esp32spi_simpletest.py - ESP + Requests

Code done running. Waiting for reload.
soft reboot

Auto-reload is on. Simply save files over USB to run them or enter REPL to disable.
code.py output:
ESP32 SPI webclient test
ESP32 found and in idle mode
Firmware vers. bytearray(b'1.2.2\x00')
MAC addr: ['SNIP', '0x31', '0xe', '0x33', '0x4f', '0xc4']
SNIP
Connecting to AP...
Connected to SNIP   RSSI: -48
My IP address is SNIP
IP lookup adafruit.com: SNIP
Ping google.com: 10 ms
Fetching text from http://wifitest.adafruit.com/testwifi/index.html
----------------------------------------
This is a test of Adafruit WiFi!
If you can read this, its working :)

----------------------------------------

Fetching json from http://api.coindesk.com/v1/bpi/currentprice/USD.json
----------------------------------------
{'time': {'updated': 'Aug 29, 2019 16:28:00 UTC', 'updatedISO': '2019-08-29T16:28:00+00:00', 'updateduk': 'Aug 29, 2019 at 17:28 BST'}, 'disclaimer': 'This data was produced from the CoinDesk Bitcoin Price Index (USD). Non-USD currency data converted using hourly conversion rate from openexchangerates.org', 'bpi': {'USD': {'code': 'USD', 'description': 'United States Dollar', 'rate_float': 9504.23, 'rate': '9,504.2283'}}}
----------------------------------------
Done!

esp32spi_aio_post.py - WiFiManager + Requests

code.py output:
ESP32 SPI webclient test
Posting data...{'lat': None, 'feed_id': 997503, 'ele': None, 'expiration': '2019-10-28T16:29:22Z', 'id': '0E82Q1KT67MR5XGEDR29EW84KM', 'lon': None, 'value': '0', 'feed_key': 'test', 'location': None, 'created_at': '2019-08-29T16:29:22Z', 'created_epoch': 1567096162}
OK

esp32spi_wsgiserver.py - server + esp

ESP32 SPI simple web server test!
open this IP in your browser:  SNIP
closing
closing
closing
{'b': 240, 'g': 255, 'r': 133}
closing
{'b': 255, 'g': 250, 'r': 121}

[ladyada]

to ease the transition please have a write = send function assignment so either works

[brentru]

@ladyada added and tested with the current (pre-PR'd) version of requests

[ladyada]

make a note this is deprecated, and will be removed

[brentru]

noted!