fix(ansible): avoid a deprecation warning

Author: gforcada

ansible.yml

@@ -3,7 +3,7 @@
   roles:
     - ansible-compile-python
   vars:
-    - python_24: true
-    - python_26: true
-    - pillow: true
-    - lxml: true
+    python_24: true
+    python_26: true
+    pillow: true
+    lxml: true