add TLS_mode conntype, assertion for connecting to HTTPS

Author: brentru

adafruit_wiznet5k/adafruit_wiznet5k.py

@@ -151,6 +151,7 @@ class WIZNET5K: # pylint: disable=too-many-public-methods
 
     TCP_MODE = const(0x21)
     UDP_MODE = const(0x02)
+    TLS_MODE = const(0x03) # This is NOT currently implemented
 
     # pylint: disable=too-many-arguments
     def __init__(self, spi_bus, cs, reset=None,

adafruit_wiznet5k/adafruit_wiznet5k_socket.py

@@ -141,6 +141,7 @@ def connect(self, address, conntype=None):
         :param tuple address: Remote socket as a (host, port) tuple.
 
         """
+        assert conntype != 0x03, "Error: SSL/TLS is not currently supported by CircuitPython."
         host, port = address
 
         if hasattr(host, 'split'):