Add contribution guidance

Add CONTRIBUTING.md that points to the same document in chef-cookbooks
Add mention of the contribution document in the top of the README.md
Merge pull request #13 from claco/contributing

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more ha keepalived work
add package names for rpm based systems
Fix FC024 violation
Merge pull request #14 from rackerjoe/ha_rabbit_part3

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version bump
don't remove iptables rules on failover
Merge pull request #15 from rackerjoe/master

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Merge branch 'havana' of https://github.com/rcbops-cookbooks/keepalived into havana
Version Bump to 4.1.3
Merge pull request #16 from rackerjoe/master

Version Bump to 4.1.3
move version out of metadata.rb into VERSION
Merge pull request #17 from rackerjoe/master

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add a separate update script for redhat and centos
Merge pull request #18 from rackerjoe/master

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merge master to havana branch
Merge branch 'havana' of github.com:rcbops-cookbooks/keepalived
fix a typo in iptables check
Merge pull request #19 from rackerjoe/master

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