Update git submodules

* Update docs/submodules/integration.git from branch 'master'
  to 64efe1db468feba9ec568015533609a1dc6a78f1
  - Use demo 1.4.0 release artifacts in robot
    
    Issue-ID: INT-1055
    Signed-off-by: Gary Wu <gary.wu@futurewei.com>
    Change-Id: I8d42789049d655155b84455264c8382e08c3dda9
    
diff --git a/docs/submodules/integration.git b/docs/submodules/integration.git
index 21b09c9..64efe1d 160000
--- a/docs/submodules/integration.git
+++ b/docs/submodules/integration.git
@@ -1 +1 @@
-Subproject commit 21b09c956609d3ebee0081686802d20da194c523
+Subproject commit 64efe1db468feba9ec568015533609a1dc6a78f1