Update git submodules

* Update docs/submodules/appc.git from branch 'master'
  to 6e31b176be9421c154ac7d164254d9df31d68d56
  - added assert statements in jUnits
    
    Issue-ID: APPC-1859
    Change-Id: I80ce69ae34b7560bef1b1be06b8c3bb9fef73e22
    Signed-off-by: Rupinder <rupinsi1@in.ibm.com>
    
1 file changed