index.html: Add EPEL 6 & 7 info
index.html: Add EPEL 6 & 7 info

Since we have both EPEL 6 & 7 mirrored, I think we should provide links
to both yum repo files.

This commit fixes issue #3 on GitHub[1].

1. https://github.com/oguya/mirror.mjanja.co.ke/issues/3

Signed-off-by: James Oguya <519541004f985a2342cd065b631d21accf41fddb@gmail.com>

oguya/mirror.mjanja.co.ke,ilri/hpc.ilri.cgiar.org-mirror