v2015.08.06: * Fix python-requests installations for Ubuntu >= 14.04 LTS. #631, #632, #633 * Install python-crypto from Chris Lea's PPA for Ubuntu < 14.04 * Exit the git checkout directory before deleting it. Thanks Bret Fisher. #634 * Use prefix /usr for centos git install. Thanks Stanislav B. #638 * Drop Ubuntu EOL versions. All Ubuntu version before 12.04. * Make sure python-dev is installed wheb trying to install tornado from PyPi. #640