Add latest Ansible versions (2.5.9, 2.6.4)

Author: tersmitten

.travis.yml

@@ -7,10 +7,12 @@ python: "2.7"
 
 env:
   - ANSIBLE_VERSION=latest
+  - ANSIBLE_VERSION=2.6.4
   - ANSIBLE_VERSION=2.6.3
   - ANSIBLE_VERSION=2.6.2
   - ANSIBLE_VERSION=2.6.1
   - ANSIBLE_VERSION=2.6.0
+  - ANSIBLE_VERSION=2.5.9
   - ANSIBLE_VERSION=2.5.8
   - ANSIBLE_VERSION=2.5.7
   - ANSIBLE_VERSION=2.5.6