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##### SUMMARY
<!--- Explain the problem briefly below -->
Unit tests for ios_interfaces is failing, with import error

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
ios_interfaces
##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
devel
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
macos

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
Unit tests for `ios_interfaces` should pass w/o any issue/failure

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
Unit tests are failing with error: `ImportError: cannot import name 'dict_diff' from 'ansible.module_utils.network.ios.utils.utils'`
<!--- Paste verbatim command output between quotes -->
```paste below

```

""" Collect the configuration from the args passed to the module,
            collect the current configuration (as a dict from facts)
        :rtype: A list
        :returns: the commands necessary to migrate the current configuration
                  to the deisred configuration
        """
        want = self._module.params['config']
        have = existing_interfaces_facts
        resp = self.set_state(want, have)
        return to_list(resp)
    def set_state(self, want, have):
        """ Select the appropriate function based on the state provided
        :param want: the desired configuration as a dictionary
        :param have: the current configuration as a dictionary
        :rtype: A list
        :returns: the commands necessary to migrate the current configuration
                  to the deisred configuration
        """
        commands = []
        state = self._module.params['state']
        if state == 'overridden':
            commands = self._state_overridden(want, have)
        elif state == 'deleted':
            commands = self._state_deleted(want, have)
        elif state == 'merged':
            commands = self._state_merged(want, have)
        elif state == 'replaced':
            commands = self._state_replaced(want, have)
        return commands
    def _state_replaced(self, want, have):