Adding vitalsd to the build

Change-Id: I75d7dfb5d293169537c56e3a20542557a9d2b94b

mendel.xml

diff --git a/mendel.xml b/mendel.xml
index 521d0c3..6648852 100644
--- a/mendel.xml
+++ b/mendel.xml
@@ -30,6 +30,7 @@
     <project path="packages/mendel-minimal" name="aiy-board-tweaks" />
     <project path="packages/runonce" name="runonce" />
     <project path="packages/usb-gadget" name="usb-gadget" />
+    <project path="packages/vitalsd" name="vitalsd" />
 
     <!-- END Package repos -->