Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Add missing unit tests for utils files

    JIRA: DOVETAIL-724

    This patch adds unit tests which were missing from dovetail code base.
    Furthermore it updates the test_parser existing unit test. Finally,
    it fixes some minor issues in dovetail_utils itself.

    Change-Id: I8fd7cd4f6b1ede11664914746d2279f062511639
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>
  - Improve tox testing

    This patch removes unused test requirements. In addition, it runs
    coverage together with unit tests by py.test. In addition, it adds
    sone docs links which were missing. Finally, it adds coverage reports
    to .gitignore file.

    Change-Id: I68e65781b17929c60fbb3f4c318b1366c35d185f
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>