I wrote a script for creating maps by using perlin noise. It is very simple and can be easily expanded upon, for example texturing or trees and rivers could be added. An example can be found here ID:2140138. 

perlin noise generator: https://pastebin.com/mk9NutMN

map creator: https://pastebin.com/MGXh72ca

(inspired by http://flafla2.github.io/2014/08/09/perlinnoise.html)

You can use the script manager and put the files into the scripts folder. Then select it and it should do its thing.

In this updated version you could also change values from the console and then run genMap() to draw the Map

updated version: https://pastebin.com/aXqLd45f

It also offers some shading.

I am still working on it so it isn't userfriendly at all.(sorry)