Text centers vertically much better

Author: Melissa LeBlanc-Williams

adafruit_button.py

@@ -140,7 +140,7 @@ def __init__(self, *, x, y, width, height, name=None, style=RECT,
                 raise RuntimeError("Button not large enough for label")
             self.label = Label(label_font, text=label)
             self.label.x = x + (width - dims[2]) // 2
-            self.label.y = y + (height - dims[3])
+            self.label.y = y + height // 2
             self.label.color = label_color
             self.group.append(self.label)