make sure format_string works with no formats

Author: MrPowers

tests/conftest.py

@@ -5,7 +5,7 @@
 class MyFormats:
     mismatched_rows = ["light_yellow"]
     matched_rows = ["cyan", "bold"]
-    mismatched_cells = ["purple", "blink"]
+    mismatched_cells = ["purple"]
     matched_cells = ["blue"]
 
 @pytest.fixture()

tests/test_terminal_str_formatter.py

@@ -5,3 +5,7 @@
 
 def test_it_can_make_a_blue_string():
     print(format_string("hi", ["bold", "blink"]))
+
+
+def test_it_works_with_no_formats():
+    print(format_string("hi", []))