def login
      response = @client.call(:login,
        cookies: @auth_cookie,
        message: {
          username: @username, 
          password: decrypt(@password)
        })

      @auth_cookie = response.http.cookies if @auth_cookie.nil?
      @login_token = response.hash[:envelope][:body][:login_response][:login_result]
      response
    end
def login
      response = @client.call(:login,
        cookies: @auth_cookie,
        message: {
          username: @username, 
          password: decrypt(@password)
        })

      @auth_cookie = response.http.cookies if @auth_cookie.nil?
      @login_token = response.hash[:envelope][:body][:login_response][:login_result]
      response
    end
Public: Login to Birst using the username and password.  After login,
 the auth cookie and login token are captured and stored as an instance
 variable.

 Returns the Savon response.