requests.get() throws an exception in aws lambda

I'm not able to make HTTP calls from python based lambda function hosted on AWS and managed through Serverless framework.

I've tried using botocore.vendored requests module but it shows deprecation warning and suggested to use the requests module itself.

url = V2_URL + '/api/analytics/validate/' + smId
headers = {
    'Content-Type':'application/json',
    'Authorization': token
}

response = requests.get(url, headers=headers)

print('Result: ')
print(response.content)

In Cloudwatch, I see this stack trace:

[ERROR] UnboundLocalError: local variable 'response' referenced before assignment
Traceback (most recent call last):
  File "/var/task/serverless_sdk/__init__.py", line 97, in wrapped_handler
    return user_handler(event, context)
  File "src/authorize.py", line 21, in validate
    principal_id = verify_token(whole_auth_token, event['pathParameters']['smId'])
  File "src/authorize.py", line 38, in verify_token
    response = requests.get(url, headers=headers)
  File "/var/task/requests/api.py", line 75, in get
    return request('get', url, params=params, **kwargs)
  File "/var/task/requests/api.py", line 60, in request
    return session.request(method=method, url=url, **kwargs)
  File "/var/task/requests/sessions.py", line 533, in request
    resp = self.send(prep, **send_kwargs)
  File "/var/task/requests/sessions.py", line 646, in send
    r = adapter.send(request, **kwargs)
  File "/var/task/requests/adapters.py", line 449, in send
    timeout=timeout
  File "/var/task/serverless_sdk/__init__.py", line 384, in wrapper
    if response: