test_set_charset: use utf8mb4 (PyMySQL#664)

grooverdan · methane · commit b51d5dae3910 · 2018-04-30T23:29:29.000+09:00
Works on all supported MySQL versions now that 5.1 support is
dropped.
diff --git a/pymysql/tests/test_connection.py b/pymysql/tests/test_connection.py
@@ -460,7 +460,7 @@ def test_context(self):
 
     def test_set_charset(self):
         c = self.connect()
-        c.set_charset('utf8')
+        c.set_charset('utf8mb4')
         # TODO validate setting here
 
     def test_defer_connect(self):
