Support Python 3.5

Minor refactor of test code, even though test data is all 7-bit ASCII clean
add explicit encoding to all conversions.

Added python 3.4 and 3.5 to TravisCI - no doc changes. Primary focus is 3.6 and 2.7.

Author: clach04

.travis.yml

@@ -1,6 +1,8 @@
 language: python
 python:
   - "2.7"
+  - "3.4"
+  - "3.5"
   - "3.6"
 # command to install dependencies
 install:

tests.py

@@ -33,9 +33,9 @@ def check_data_frame(data, expected_prefix, encrypted=True):
         checksum = data[19:35]
         encrypted_json = data[35:-8]
 
-        json_data = pytuya.AESCipher(LOCAL_KEY.encode('utf-8')).decrypt(encrypted_json)
+        json_data = pytuya.AESCipher(LOCAL_KEY.encode(mock_byte_encoding)).decrypt(encrypted_json)
     else:
-        json_data = data[16:-8].decode('utf-8')
+        json_data = data[16:-8].decode(mock_byte_encoding)
 
     frame_ok = True
     if prefix != pytuya.hex2bin(expected_prefix):
@@ -103,8 +103,9 @@ def test_set_timer(self):
         mock_send_receive_set_timer.call_counter = 0
         result = d.set_timer(6666)
         result = result[result.find(b'{'):result.rfind(b'}')+1]
-        result = json.loads(result.decode())
-        
+        result = result.decode(mock_byte_encoding)  # Python 3 (3.5.4 and earlier) workaround to json stdlib "behavior" https://docs.python.org/3/whatsnew/3.6.html#json
+        result = json.loads(result)
+
         # Make sure mock_send_receive_set_timer() has been called twice with correct parameters
         self.assertEqual(result['test_result'], "SUCCESS")
 
@@ -113,8 +114,9 @@ def test_set_status(self):
         d._send_receive = MagicMock(side_effect=mock_send_receive_set_status)
 
         result = d.set_status(True, 1)
-        result = json.loads(result.decode())
-        
+        result = result.decode(mock_byte_encoding)  # Python 3 (3.5.4 and earlier) workaround to json stdlib "behavior" https://docs.python.org/3/whatsnew/3.6.html#json
+        result = json.loads(result)
+
         # Make sure mock_send_receive_set_timer() has been called twice with correct parameters
         self.assertEqual(result['test_result'], "SUCCESS")