Hammer CLI

At the very least we should allow to use JSON to provide the value

--os-parameters-attributes="[{\"name\":\"test\", \"value\":1}]" 

That possibility should be mentioned in the help. We may be able to construct and example based on the param description.

 --os-parameters-attributes OS_PARAMETERS_ATTRIBUTES   Array of parameters
                                                       Comma separated list of values. Values containing comma should be quoted or escaped with backslash

Is really hard to use without consulting the API docs.

We may think of something like following for the List normalizer to allow the JSON input.

         def format(val)
-          (val.is_a?(String) && !val.empty?) ? HammerCLI::CSVParser.new.parse(val) : []
+          return [] unless val.is_a?(String) && !val.empty?
+          begin
+              formatter = JSONInput.new
+              formatter.format(val)
+          rescue ArgumentError
+            HammerCLI::CSVParser.new.parse(val)
+          end
         end