Add bounds check for array in the median/mode calculation routine

Author: TheKitty

Trinket_Ultrasonic_Rangefinder/code.py

@@ -80,6 +80,12 @@ def find_mode(x):
     should mode not be found
     """
     n = len(x)
+    
+    if n == 0:    # If somehow there is a null array
+        return 0;
+    
+    if n == 1:        # In trivial case of a one element array
+        return x[0];  #   just return the element as the mode.
 
     max_count = 0
     mode = 0