Enhance user experience with more energetic response
Enhance user experience with more energetic response

Previous standard output of the thirteen() function did not sufficiently convey how revolutionary the project is to arithmetic and indeed mathematics as we understand it. Adding exclamation points helps communicate the proper element of surprise. This does not cause the overall 'thirteen()' function to break.
hdh3000/thirteen,stevenlundy/thirteen,valgaze/thirteen,coreysf/thirteen,phillipalexander/thirteen,garrettmaring/thirteen,coldzonemt/thirteen,mochuelo-kun/thirteen,heidikumar/thirteen,RFenolio/thirteen,jessicalc/thirteen