Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Fix syntax error on clean_results_dir method

    Change-Id: I9f33bb320452efab79be5a22e625efac820183eb
    Signed-off-by: Panagiotis Karalis <pkaralis@intracom-telecom.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 09f11fb..64c1fc7 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 09f11fb9313e668bc293ca19a2760c3c3bae40a1
+Subproject commit 64c1fc7a32b892e353c0e6a092110a9268423c7b