Update to fill/outline color check

The current code doesn't draw the button if both fill and outline are 0x000000 (black). With the proposed change, if either the outline or the fill have been assigned any value, the check will pass. If fill and outline are both None, nothing will be drawn.

Author: jpecor

adafruit_button.py

@@ -111,8 +111,8 @@ def __init__(self, *, x, y, width, height, name=None, style=RECT,
             self.selected_fill = (~self.fill_color) & 0xFFFFFF
         if self.selected_outline is None and outline_color is not None:
             self.selected_outline = (~self.outline_color) & 0xFFFFFF
-
-        if outline_color or fill_color:
+       
+        if (outline_color is not None) or (fill_color is not None):
             if style == Button.RECT:
                 self.body = Rect(x, y, width, height,
                                  fill=self.fill_color, outline=self.outline_color)