add note for centos 6.6 that it is puppet v4.2.2 specific
add note for centos 6.6 that it is puppet v4.2.2 specific

circonus-labs/circonus-one-step-install,maier/circonus-one-step-install,maier/circonus-one-step-install,maier/circonus-one-step-install,circonus-labs/circonus-one-step-install,circonus-labs/circonus-one-step-install