Fix formatting of quaternion function

...to satisfy black. To close Issue #113.

Author: pjjefferies

adafruit_bno055.py

@@ -460,7 +460,9 @@ def _euler(self) -> None:
         raise NotImplementedError("Must be implemented.")
 
     @property
-    def quaternion(self) -> Tuple[Optional[float], Optional[float], Optional[float], Optional[float]]:
+    def quaternion(
+        self,
+    ) -> Tuple[Optional[float], Optional[float], Optional[float], Optional[float]]:
         """Gives the calculated orientation as a quaternion.
         Returns an empty tuple of length 4 when this property has been disabled by the current mode.
         """