Another fix for Travis CI tests.

Author: geerlingguy

.travis.yml

@@ -4,7 +4,7 @@ services: docker
 
 install:
   # Install Ansible.
-  - pip install ansible
+  - pip install ansible docker-py
 
   # Install role dependencies.
   - ansible-galaxy install -r requirements.yml

README.md

@@ -93,6 +93,8 @@ Then, make sure Docker is running, and run the playbook to build the container:
 
 Once the image is built, you can run `docker images` to see the `php-apache` image that was generated.
 
+> Note: If you get an error like `Failed to import docker-py`, run `pip install docker-py`.
+
 ### Push the image to Docker Hub
 
 Currently, the process for updating this image on Docker Hub is manual. Eventually this will be automated via Travis CI.