增加vivo支付与登录接口

package/pay/vivo/client.go

@@ -0,0 +1,15 @@
+package vivo
+
+type Pay struct {
+	AppId     string
+	AppKey    string
+	AppSecret string
+}
+
+func New(appId, appKey, appSecret string) (client *Pay) {
+	return &Pay{
+		AppId:     appId,
+		AppKey:    appKey,
+		AppSecret: appSecret,
+	}
+}