Delete internal directory

internal/vision/client_test.go

@@ -1,12 +0,0 @@
-package vision
-
-import "testing"
-
-func TestLooksLikeCaptchaQuestion(t *testing.T) {
-	if !looksLikeCaptchaQuestion("识别验证码，只输出字符") {
-		t.Fatal("expected captcha hint")
-	}
-	if looksLikeCaptchaQuestion("描述登录页布局") {
-		t.Fatal("expected non-captcha")
-	}
-}