switch to gpt partitioning

[bootimage] / initrd.img

diff --git a/initrd.img b/initrd.img
new file mode 120000 (symlink)
index 0000000..aa779de
--- /dev/null
+++ b/initrd.img
@@ -0,0 +1 @@
+stretch_uefi_root/initrd.img
\ No newline at end of file