chore: Update to cfn-model 0.6.8

Author: arothian

cfn-nag.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |s|
   # versus what we used to run tests in cfn-nag before publishing cfn-nag
   # they are coupled and we are doing a good bit of experimenting in cfn-model
   # i might consider collapsing them again....
-  s.add_runtime_dependency('cfn-model', '0.6.6')
+  s.add_runtime_dependency('cfn-model', '0.6.8')
   s.add_runtime_dependency('logging', '~> 2.2.2')
   s.add_runtime_dependency('netaddr', '~> 2.0.4')
   s.add_runtime_dependency('optimist', '~> 3.0.0')