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##### SUMMARY
With addition of OAuthClient in snow_* modules, I am getting following error - 
```
Traceback (most recent call last):
  File "/Users/akasurde/.ansible/tmp/ansible-tmp-1563543375.7458959-114877035679906/AnsiballZ_snow_record.py", line 125, in <module>
    _ansiballz_main()
  File "/Users/akasurde/.ansible/tmp/ansible-tmp-1563543375.7458959-114877035679906/AnsiballZ_snow_record.py", line 117, in _ansiballz_main
    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)
  File "/Users/akasurde/.ansible/tmp/ansible-tmp-1563543375.7458959-114877035679906/AnsiballZ_snow_record.py", line 51, in invoke_module
    spec.loader.exec_module(module)
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/tmp/ansible_snow_record_payload_brr2thzt/__main__.py", line 339, in <module>
  File "/tmp/ansible_snow_record_payload_brr2thzt/__main__.py", line 335, in main
  File "/tmp/ansible_snow_record_payload_brr2thzt/__main__.py", line 205, in run_module
  File "/tmp/ansible_snow_record_payload_brr2thzt/ansible_snow_record_payload.zip/ansible/module_utils/service_now.py", line 57, in login
AttributeError: 'NoneType' object has no attribute 'generate_token'
```

##### ISSUE TYPE
- Bug Report

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

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.9
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
Nothing specific
```

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

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

<!--- Paste example playbooks or commands between quotes below -->
```yaml
---
- hosts: localhost
  tasks:
    - snow_record:
        instance: "instance_id"
        password: "password"
        username: admin
        data:
          short_description: "Description"
          priority: 2
        state: present
```

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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->
Playbook should be successful.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Traceback (most recent call last):
  File "/Users/akasurde/.ansible/tmp/ansible-tmp-1563543375.7458959-114877035679906/AnsiballZ_snow_record.py", line 125, in <module>
    _ansiballz_main()
  File "/Users/akasurde/.ansible/tmp/ansible-tmp-1563543375.7458959-114877035679906/AnsiballZ_snow_record.py", line 117, in _ansiballz_main
    invoke_module(zipped_mod, temp_path, ANSIBALLZ_PARAMS)
  File "/Users/akasurde/.ansible/tmp/ansible-tmp-1563543375.7458959-114877035679906/AnsiballZ_snow_record.py", line 51, in invoke_module
    spec.loader.exec_module(module)
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/tmp/ansible_snow_record_payload_brr2thzt/__main__.py", line 339, in <module>
  File "/tmp/ansible_snow_record_payload_brr2thzt/__main__.py", line 335, in main
  File "/tmp/ansible_snow_record_payload_brr2thzt/__main__.py", line 205, in run_module
  File "/tmp/ansible_snow_record_payload_brr2thzt/ansible_snow_record_payload.zip/ansible/module_utils/service_now.py", line 57, in login
AttributeError: 'NoneType' object has no attribute 'generate_token'
```

client_secret: "Password1!"
    instance: dev99999
    table: incident
    query:
      assignment_group: d625dccec0a8016700a222a0f7900d06
    return_fields:
      - number
      - opened_at
- name: Find open standard changes with my template
  snow_record_find:
    username: ansible_test
    password: my_password
    instance: dev99999
    table: change_request
    query:
      AND:
        equals:
          active: "True"
          type: "standard"
          u_change_stage: "80"
        contains:
          u_template: "MY-Template"
    return_fields:
      - sys_id
      - number
      - sys_created_on
      - sys_updated_on
      - u_template
      - active
      - type