Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Improve Dockerfile

    This patch improves the Dockerfile which produces the Dovetail image.

    Change-Id: I65e65f155afe237b11c668e6486e48b55cc7e96c
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index ef2d528..f27b138 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit ef2d5282306a277e591aa3c355277c6f158d8e76
+Subproject commit f27b1382a87c432487816cfad6e5c341250d16b2