Use Go1.11 module (#5743)

* Migrate to go modules

* make vendor

* Update mvdan.cc/xurls

* make vendor

* Update code.gitea.io/git

* make fmt-check

* Update github.com/go-sql-driver/mysql

* make vendor

vendor/github.com/go-macaron/captcha/.travis.yml

@@ -0,0 +1,14 @@
+sudo: false
+language: go
+
+go:
+  - 1.3
+  - 1.4
+  - 1.5
+  - tip
+
+script: go test -v -cover -race
+
+notifications:
+  email:
+    - u@gogs.io

vendor/github.com/go-macaron/captcha/README.md

@@ -0,0 +1,16 @@
+# captcha [![Build Status](https://travis-ci.org/go-macaron/captcha.svg?branch=master)](https://travis-ci.org/go-macaron/captcha)
+
+Middleware captcha provides captcha service for [Macaron](https://github.com/go-macaron/macaron).
+
+### Installation
+
+	go get github.com/go-macaron/captcha
+
+## Getting Help
+
+- [API Reference](https://gowalker.org/github.com/go-macaron/captcha)
+- [Documentation](http://go-macaron.com/docs/middlewares/captcha)
+
+## License
+
+This project is under the Apache License, Version 2.0. See the [LICENSE](LICENSE) file for the full license text.