Install gcovr for code coverage reporting

Change-Id: I1a8d98bd723248c52feeba0a09c31a6d83ee6210
diff --git a/roles/virt_runc_launcher/tasks/main.yaml b/roles/virt_runc_launcher/tasks/main.yaml
index 13454e7..8042b5b 100644
--- a/roles/virt_runc_launcher/tasks/main.yaml
+++ b/roles/virt_runc_launcher/tasks/main.yaml
@@ -83,6 +83,7 @@
       - fakeroot
       - python3-devel
       - python3-pytest
+      - gcovr
 
 - name: enable sudo within the Fedora 29 image
   copy: