Clean-up handling of lowercase input.

As #22 moved the conversion to upper case into the
conversion function, it is no longer necessary to
convert it in the main function.

src/roman.py

@@ -138,8 +138,7 @@ def parse_args():
 def main():
     args = parse_args()
     if args.reverse:
-        u = args.number.upper()
-        r = fromRoman(u)
+        r = fromRoman(args.number)
         print(r)
     else:
         i = int(args.number)