Er, no, that doesn’t look right. The file you should be changing is ...\v0.6\REQUIRE, and you need to change the line with Compat. See Error with NullableArrays when trying to install or remove packages or run Pkg.update() - #6 by Harsha
It looks like you edited the wrong file (...\v0.6\Requires\REQUIRE) and changed the wrong line (the julia requirement itself).