Merge pull request #100 from EdwardBetts/spelling

correct spelling mistake

Author: sigmavirus24

requests_kerberos/kerberos_.py

@@ -232,7 +232,7 @@ def handle_other(self, response):
                     return response
             else:
                 # Unable to attempt mutual authentication when mutual auth is
-                # required, raise an exception so the user doesnt use an
+                # required, raise an exception so the user doesn't use an
                 # untrusted response.
                 log.error("handle_other(): Mutual authentication failed")
                 raise MutualAuthenticationError("Unable to authenticate "