Remove skip

Author: charlesdong1991

pandas/tests/plotting/test_converter.py

@@ -28,7 +28,6 @@
 pytest.importorskip("matplotlib.pyplot")
 
 
-@pytest.mark.skip(reason="There is no warnings in some versions.")
 def test_initial_warning():
  code = (
  "import pandas as pd; import matplotlib.pyplot as plt; "