'Sign a request
Reminder: Created this function so incase
if I need to add anything to request before signing
Args:
req: The OAuth request created via _makeOAuthRequest
signate_method:
The oauth signature method to use'

def _signRequest(self, req, signature_method=oauth.OAuthSignatureMethod_HMAC_SHA1()):

    req.sign_request(signature_method, self._Consumer, self._access_token)
