Set directory paths used with dedicated build node

Change-Id: Ie1b6301e5cd788504d792af387c976339ce17f13
diff --git a/config/default.yml b/config/default.yml
index 9489ac7..3799407 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -20,6 +20,9 @@
   # directories on the head node that the cord dir is copied to, and profile is created in
   cord_dir: '/opt/cord'
   cord_profile_dir: '/opt/cord_profile'
+  credentials_dir: '/opt/credentials'
+  pki_dir: '/opt/pki'
+  ssh_pki_dir: '/opt/ssh_pki'
 
   # Specifies tasks within the head node provisioning not to execute, including:
   #