Fixed /pay always print help

[Aztorius]

When using /pay command, it will always print the result of craftconomy help command. A way of fixing this is using a custom SubCommand because the current one doesn't work with only 1 argument like /pay, but works with /money pay when there is 2 arguments. And this is done in these commits. /money pay will continue to work, but now /pay will also work.