Update kitchen image version, change linux locales for tests

Change-Id: I5b146c466d9ee4110fd54e0421e944524641e9f6
diff --git a/tests/pillar/system.sls b/tests/pillar/system.sls
index bcbfa08..eb6201e 100644
--- a/tests/pillar/system.sls
+++ b/tests/pillar/system.sls
@@ -204,10 +204,10 @@
         key_url: http://apt-mk.mirantis.com/public.gpg
         architectures: amd64
     locale:
-      en_US.UTF-8:
+      en_US:
         enabled: true
         default: true
-      "cs_CZ.UTF-8 UTF-8":
+      cs_CZ:
         enabled: true
     autoupdates:
       enabled: true