Merge pull request 'fix bad math result spam' (#5) from yagich/bankerbot-rb:fix/fix-bad-math-spam into main

Reviewed-on: #5

coin.rb

@@ -167,7 +167,7 @@ bot.message(in: Integer(ENV['BOT_CHANNEL'])) do |event|
 
   if result == user_result
     get_coin(event, MATH_PROBLEM_COIN_GAIN)
-  else
+  elsif user_result.is_a? Integer
     event.respond "Nice try, but you're wrong!"
   end
 end