added a simple test for colored_warning

Author: dantownsend

tests/utils/test_warnings.py

@@ -0,0 +1,11 @@
+from unittest import TestCase
+
+from piccolo.utils.warnings import colored_warning
+
+
+class TestColoredWarning(TestCase):
+    def test_colored_warning(self):
+        """
+        Just make sure no errors are raised.
+        """
+        colored_warning(message="TESTING!")