Bump ratpack template version to 0.3.1.
Bump ratpack template version to 0.3.1.

ctran/lazybones,pledbrook/lazybones,pledbrook/lazybones-kotlin,pledbrook/lazybones-kotlin,aaronzirbes/lazybones,danielgrycman/lazybones,pledbrook/lazybones,ctran/lazybones,danielgrycman/lazybones