Support for IPv6

Passing the test is pending on 
serverspec/specinfra#210
serverspec/serverspec#469

-----> Starting Kitchen (v1.2.2.dev)
-----> Verifying <ipv6-list-of-tables-centos-65>...
       Removing /tmp/busser/suites/serverspec
       Uploading /tmp/busser/suites/serverspec/list_of_tables_spec.rb
(mode=0644)
-----> Running serverspec test suite
       /opt/chef/embedded/bin/ruby -I/tmp/busser/suites/serverspec -S
/opt/chef/embedded/bin/rspec /tmp/busser/suites/
serverspec/list_of_tables_spec.rb --color --format documentation

       iptables
         should have rule "-A INPUT -j simple_rule"
         should have rule "-A simple_rule -p tcp -m tcp --dport 80 -j ACCEPT"
         should have rule "-A INPUT -p tcp -m tcp --dport 81 -j ACCEPT"
         should have rule "-A FORWARD -p tcp -m tcp --dport 82 -j ACCEPT"
         should have rule "-A INPUT -m state --state NEW -j jump_with_rule"
         should have rule "-A jump_with_rule -p tcp -m tcp --dport 83 -j ACCEPT"
         should have rule "-A array_of_rules -p tcp -m tcp --dport 84 -j ACCEPT"
         should have rule "-A array_of_rules -p tcp -m tcp --dport 85 -j ACCEPT"
         should have rule "-A INPUT -j array_of_rules"
         should not have rule "*nat"
         should have rule "*mangle"
         should have rule "*filter"
         should not have rule "*raw"

       ip6tables
         should have rule "-A INPUT -j simple_rule"
         should have rule "-A simple_rule -p tcp -m tcp --dport 80 -j ACCEPT"
         should have rule "-A INPUT -p tcp -m tcp --dport 81 -j ACCEPT"
         should not have rule "-A FORWARD -p tcp -m tcp --dport 82 -j ACCEPT"
         should not have rule "-A INPUT -m state --state NEW -j jump_with_rule"
         should not have rule "-A jump_with_rule -p tcp -m tcp --dport 83 -j ACCEPT"
         should have rule "-A array_of_rules -p tcp -m tcp --dport 84 -j ACCEPT"
         should have rule "-A array_of_rules -p tcp -m tcp --dport 85 -j ACCEPT"
         should have rule "-A INPUT -j array_of_rules"
         should not have rule "*nat"
         should have rule "*mangle"
         should have rule "*filter"
         should not have rule "*raw"

       Finished in 0.23916 seconds
       26 examples, 0 failures
       Finished verifying <ipv6-list-of-tables-centos-65> (0m1.63s).
-----> Kitchen is finished. (0m2.37s)