Update README with get_last_authn_contexts method

Author: pitbulk

README.md

@@ -915,6 +915,7 @@ Main class of OneLogin Python Toolkit
 * ***get_sso_url*** Gets the SSO url.
 * ***get_slo_url*** Gets the SLO url.
 * ***get_last_request_id*** The ID of the last Request SAML message generated (AuthNRequest, LogoutRequest).
+* ***get_last_authn_contexts*** Returns the list of authentication contexts sent in the last SAML Response.
 * ***build_request_signature*** Builds the Signature of the SAML Request.
 * ***build_response_signature*** Builds the Signature of the SAML Response.
 * ***get_settings*** Returns the settings info.

src/onelogin/saml2/auth.py

@@ -322,7 +322,7 @@ def get_last_assertion_id(self):
 
     def get_last_authn_contexts(self):
         """
-        :returns: The list of authentication contexts sent in the last SAML resposne.
+        :returns: The list of authentication contexts sent in the last SAML Response.
         :rtype: list
         """
         return self.__last_authn_contexts