<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
Add new commands to the Redfish remote_management modules to perform firmware update requests.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
redfish_config.py
redfish_utils.py

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->
Operators need a way to update firmware on Redfish managed systems. Would like an extension made to be able to perform SimpleUpdate actions with a specified firmware image. At the very minimum we can point to a remote HTTP/TFTP/SCP/etc server, but if possible, it might be good to spin up a lightweight HTTP server to service the request in case one isn't provisioned.

<!--- Paste example playbooks or commands between quotes below -->
```yaml
  - name: Pull style update
    redfish_config:
      category: Update
      command: PullUpdate
      image: http://my.file.repo/someimage.bin
      targets:
        - /redfish/v1/Systems/1
        - /redfish/v1/Systems/2
      baseuri: "{{ baseuri }}"
      username: "{{ username }}"
      password: "{{ password }}"
```

<!--- HINT: You can also paste gist.github.com links for larger files -->

if user.get('account_id'):
            
            response = self._find_account_uri(acct_id=user.get('account_id'))
        else:
            
            response = self._find_empty_account_slot()
        if not response['ret']:
            return response
        uri = response['uri']
        payload = {}
        if user.get('account_username'):
            payload['UserName'] = user.get('account_username')
        if user.get('account_password'):
            payload['Password'] = user.get('account_password')
        if user.get('account_roleid'):
            payload['RoleId'] = user.get('account_roleid')
        response = self.patch_request(self.root_uri + uri, payload)
        if response['ret'] is False:
            return response
        return {'ret': True}
    def add_user(self, user):