pytests/test_panel_brightness.py: make range inclusive

If panel is set to 100% test would fail so include the top of the range.

Signed-off-by: Angus Ainslie <angus@akkea.ca>

pytests/test_panel_brightness.py

@@ -10,4 +10,4 @@ def test_panel_brightness():
     else:
         upper = 101
     f = open(os.path.join(path, 'brightness'))
-    assert int(f.read()) in range(0, upper)
+    assert int(f.read()) in range(0, upper + 1)