feat: Add reverse mode test case

Author: yangtzech

tests/test_pure_pursuit.py

@@ -6,6 +6,10 @@ def test1():
     m.show_animation = False
     m.main()
 
+def test_backward():
+    m.show_animation = False
+    m.is_reverse_mode = True
+    m.main()
 
 if __name__ == '__main__':
     conftest.run_this_test(__file__)