Use socket.recv instead of socket.read

[brentru]

Switching socket.read to socket.recv to match the CircuitPython Socket API and the CPython Socket API.

• read now calls recv, has a note regarding future depreciation

MiniMQTT and Requests are affected by this change.

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

Tests ran:
esp32spi_simpletest.py - ESP + Requests

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 21:35:00 UTC', 'updatedISO': '2019-08-29T21:35:00+00:00', 'updateduk': 'Aug 29, 2019 at 22:35 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': 9513.59, 'rate': '9,513.5900'}}}
----------------------------------------
Done!

esp32spi_aio_post.py - WiFiManager + Requests

ESP32 SPI webclient test
Posting data...{'lat': None, 'feed_id': 997503, 'ele': None, 'expiration': '2019-10-28T21:36:43Z', 'id': '0E82WHFFNKECTNQ5JZP2DVH7C8', 'lon': None, 'value': '0', 'feed_key': 'test', 'location': None, 'created_at': '2019-08-29T21:36:43Z', 'created_epoch': 1567114603}
OK
Posting data...{'lat': None, 'feed_id': 997503, 'ele': None, 'expiration': '2019-10-28T21:37:02Z', 'id': '0E82WHN3B7J3DMSETJ1Y0QWRMZ', 'lon': None, 'value': '1', 'feed_key': 'test', 'location': None, 'created_at': '2019-08-29T21:37:02Z', 'created_epoch': 1567114622}
OK

MiniMQTT Adafruit IO Example

code.py output:
Connecting to Adafruit IO...
Connected to Adafruit IO! Listening for topic changes on snip/feeds/onoff
Sending photocell value: 0...
Sent!
Sending photocell value: 1...
Sent!
Sending photocell value: 2...
Sent!
Sending photocell value: 3...
Sent!
Sending photocell value: 4...
Sent!
Sending photocell value: 5...
Sent!