Install from pip feature

Made this small modification to allow for installation from pip
The file permissions are indeed set properly in the archive file pip uses.
It seems this is only needed on CentOS as the epel repo contains python-pip-1.3 and untar doesn't preserve file permissions in this older version of pip.
https://github.com/pypa/pip/issues/1133

On another note, on osfamily=RedHat python-pip comes from the epel repo. Is this a problem?