Add devstack base job for zuul v3

This should be managed in the devstack repo, since it's a base job to
run devstack.

Change-Id: Iffe54fbccbccd68db08f79a1b51dd7f76dbff408
Depends-On: Ie2119f24360d56690ffd772b95a9ea6b98dd4a39
diff --git a/roles/setup-stack-user/files/50_stack_sh b/roles/setup-stack-user/files/50_stack_sh
new file mode 100644
index 0000000..4c6b46b
--- /dev/null
+++ b/roles/setup-stack-user/files/50_stack_sh
@@ -0,0 +1 @@
+stack ALL=(root) NOPASSWD:ALL