Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [build.sh] Enable push, minor fixes

    * default to enable pushing to public docker registry;
    * fix prerequisites path;
    * fix unknown terminal in Jenkins jobs;

    JIRA: FUEL-383

    Change-Id: Ie27dfbca6965c218475060da390a82921799b044
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 7e825a1..8e55abc 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 7e825a17e1e31eb4010f0c646314263f26164dab
+Subproject commit 8e55abc784276aaa3dacd30b69a4729a0a439436