README needs update

[maxgmer]

I have followed the steps of getting started on android but gradle could not sync when I included the dependencies from the readme. Can anyone please look into it and update the steps?

[05nelsonm]

Also, implementing it in a project does not coincide with additions from #99 . kind of lost here and having to backtrack through all the commits atm.

[lgibson02]

I am also trying to use this library on desktop Java. Following the instructions for that on the readme doesn't work. There is no longer a gradlew.bat in the java subdirectory. It seems it was deleted for some reason in May 2019.