Missed dependency - xz-utils

xz is required for compressing results before sending them
back to Jenkins. This is not installed be default.

Change-Id: I2d9789e7041a45f13a398bd3bd9654b8ae3642df
diff --git a/openscap/map.jinja b/openscap/map.jinja
index a797bff..cf70c67 100644
--- a/openscap/map.jinja
+++ b/openscap/map.jinja
@@ -2,7 +2,8 @@
     'Debian': {
         'packages': ['libopenscap8',
                      'xccdf-benchmarks-mirantis',
-                     'python-lxml',],
+                     'python-lxml',
+                     'xz-utils',],
     },
     'RedHat': {
         'packages': ['openscap',