Fix storing token in ClientStub when config hash is given

spec/telegram/bot/client_stub_spec.rb

@@ -49,5 +49,11 @@ RSpec.describe Telegram::Bot::ClientStub do
       its(:token) { should eq args[0] }
       its(:username) { should eq args[1] }
     end
+
+    context 'when hash config is given' do
+      let(:args) { [token: 'token', username: 'superbot'] }
+      its(:token) { should eq args[0][:token] }
+      its(:username) { should eq args[0][:username] }
+    end
   end
 end