Given a parameter dict of
        {
            'Instances.SlaveInstanceType': ['m1.small'],
            'Instances.InstanceCount': ['1']
        }

        returns
        {
            "SlaveInstanceType": "m1.small",
            "InstanceCount": "1",
        }

def _get_dict_param(self, param_prefix):
        """
        Given a parameter dict of
        {
            'Instances.SlaveInstanceType': ['m1.small'],
            'Instances.InstanceCount': ['1']
        }

        returns
        {
            "SlaveInstanceType": "m1.small",
            "InstanceCount": "1",
        }
        """
        params = {}
        for key, value in self.querystring.items():
            if key.startswith(param_prefix):
                params[camelcase_to_underscores(
                    key.replace(param_prefix, ""))] = value[0]
        return params