simplify the install documentation
simplify the install documentation

Setting $GOPATH and installing go should be a prereq of go-devs.

Additionally go get -u does already the clone in src
deasmi/terraform-provider-libvirt,deasmi/terraform-provider-libvirt,dmacvicar/terraform-provider-libvirt,deasmi/terraform-provider-libvirt,dmacvicar/terraform-provider-libvirt,dmacvicar/terraform-provider-libvirt