EL5 has Sudo 1.7.2, but the distro-provided /etc/sudoers does not contain #includedir or create /etc/sudoers.d
Merge pull request #7 from erik-smit/el5fix

EL5 has Sudo 1.7.2, but the distro-provided /etc/sudoers does not contain #includedir or create /etc/sudoers.d.