pythonX.Y version is virtually provided since long[1], and
pythonXY-devel no longer provided in latest CentOS and Fedora
releases.
So switching to use pythonX.Y-devel as that will also pull pythonX.Y
as a dependency.
Additionally install pythonX.Y-pip as for rpm distros it don't install
pip via source.
[1] 75005c20f6
Change-Id: I990586cce876533c67e3da4c97d9e5995c762340
yatinkarel
f41a16c118