Update git submodules

* Update ChronoSync from branch 'master'
  to dbee9bf49a5146a2e177dc5d53d2dbb6167aeb40
  - ci: update Travis configuration
    
     * Add testing on arm64, ppc64le, and s390x with select compiler versions
       (s390x is allowed to fail due to bug #5098)
     * Drop all versions of gcc < 7 and clang < 5
     * Add clang 11 (development branch)
     * Reenable ASan on Linux with clang 7, the upstream bug has been fixed
     * Drop Xcode 9.2 (macOS 10.12 is no longer supported)
     * Upgrade Xcode 11 to 11.3
    
    Change-Id: I87c5c76ee4fd7295c4bd5ffce6a30076e0d0143e
    
  - logic: fix -Wrange-loop-construct warning with clang 10
    
    Change-Id: Ia4cd193e099b9e85da48f83087cd93482db9a628
    
  - build+ci: switch to python3
    
    Also in this commit:
     * Sync CI scripts with other projects
     * Modernize docs/conf.py
     * Cleanup README.md
     * Use the official markdown version of the GPLv3
    
    Refs: #5095
    Change-Id: Ie607fcde1f6e41fa5efbbb41b21cb08583017442
    
diff --git a/ChronoSync b/ChronoSync
index e3fe048..dbee9bf 160000
--- a/ChronoSync
+++ b/ChronoSync
@@ -1 +1 @@
-Subproject commit e3fe048411fe654b833806fbfe3460f39d6258be
+Subproject commit dbee9bf49a5146a2e177dc5d53d2dbb6167aeb40