Remove outdated documentation

This documentation was about a previous Dockerfile that was based on
RHEL and not easily buildable by people cloning this repository.

The new Dockerfile, with images available at
https://hub.docker.com/r/openshift/openshift-ansible/, is documented in
README_CONTAINER_IMAGE.md.

README_ANSIBLE_CONTAINER.md

@@ -1,15 +0,0 @@
-# Running ansible in a docker container
-* Building ansible container:
-
-  ```sh
-  git clone https://github.com/openshift/openshift-ansible.git
-  cd openshift-ansible
-  docker build --rm -t ansible .
-  ```
-* Create /etc/ansible directory on the host machine and copy inventory file (hosts) into it.
-* Copy ssh public key of the host machine to master and nodes machines in the cluster.
-* Running the ansible container:
-
-  ```sh
-  docker run -it --rm --privileged --net=host -v ~/.ssh:/root/.ssh -v /etc/ansible:/etc/ansible ansible
-  ```