This simple script allows the installation of Ansible from sources. You can specify a branch using the '-b' option, or setting the ANSIBLE_BRANCH environment variable. Using the '-c' option, or setting the ANSIBLE_CHECKOUT environment variable, you can specify a particular commit to checkout.
Example one-liner:
curl https://raw.githubusercontent.com/GetValkyrie/ansible-bootstrap/master/install-ansible.sh| sudo env ANSIBLE_BRANCH=devel /bin/sh
See the included Vagrantfile and .travis.yml for examples of methods you might want to use in your projects.