Updated format strings to remove ' literals and added invalid roll const

As per request the format strings utilizing a single quote
within the string have been modified to remove the quotes
and use the {!r} formatter. The string for invalid rolls has
also been moved to a constant for consistency with the
rest of the plugin as well as improving readability.

Author: leonthemisfit

plugins/gaming.py

@@ -17,11 +17,13 @@
 from cloudbot import hook
 
 # String constants for the coin flip function
-INVALID_NUMBER = "Invalid input '{}': not a number"
+INVALID_NUMBER = "Invalid input {!r}: not a number"
 NO_COIN = "makes a coin flipping motion"
 SINGLE_COIN = "flips a coin and gets {}."
 MANY_COINS = "flips {} coins and gets {} heads and {} tails."
 
+INVALID_ROLL = "Invalid dice roll {!r}"
+
 ROLL_LIMIT = 100  # The maximum number of times to roll or flip before approximating results
 
 whitespace_re = re.compile(r'\s+')
@@ -64,15 +66,15 @@ def dice(text, notice):
         if match:
             text, desc = match.groups()
         else:
-            notice("Invalid dice roll '{}'".format(text))
+            notice(INVALID_ROLL.format(text))
             return
 
     if "d" not in text:
         return
 
     spec = whitespace_re.sub('', text)
     if not valid_diceroll.match(spec):
-        notice("Invalid dice roll '{}'".format(text))
+        notice(INVALID_ROLL.format(text))
         return
     groups = sign_re.findall(spec)