Add borncharges test
Test old GPAW for borncharges script for simple system
see: https://wiki.fysik.dtu.dk/gpaw/tutorialsexercises/electronic/berry/berry_tutorial.html
Test old GPAW for borncharges script for simple system
see: https://wiki.fysik.dtu.dk/gpaw/tutorialsexercises/electronic/berry/berry_tutorial.html