Do an Authentricate request and save the cookie returned to be used
        on the following requests.
        Return True if the request was successfull

def authenticate(self, username: str, password: str) -> bool:
        """Do an Authentricate request and save the cookie returned to be used
        on the following requests.
        Return True if the request was successfull
        """
        self.username = username
        self.password = password

        auth_payload = """<authenticate1 xmlns=\"utcs\"
                          xmlns:i=\"http://www.w3.org/2001/XMLSchema-instance\">
                          <password>{password}</password>
                          <username>{username}</username>
                          <application>treeview</application>
                          </authenticate1>"""
        payload = auth_payload.format(password=self.password,
                                      username=self.username)

        xdoc = self.connection.soap_action(
            '/ws/AuthenticationService', 'authenticate', payload)
        if xdoc:
            isok = xdoc.find(
                './SOAP-ENV:Body/ns1:authenticate2/ns1:loginWasSuccessful',
                IHCSoapClient.ihcns)
            return isok.text == 'true'
        return False