Use vendored go-swagger (#8087)

* Use vendored go-swagger

* vendor go-swagger

* revert un wanteed change

* remove un-needed GO111MODULE

* Update Makefile

Co-Authored-By: techknowlogick <matti@mdranta.net>

vendor/github.com/go-openapi/swag/README.md

@@ -0,0 +1,22 @@
+# Swag [![Build Status](https://travis-ci.org/go-openapi/swag.svg?branch=master)](https://travis-ci.org/go-openapi/swag) [![codecov](https://codecov.io/gh/go-openapi/swag/branch/master/graph/badge.svg)](https://codecov.io/gh/go-openapi/swag) [![Slack Status](https://slackin.goswagger.io/badge.svg)](https://slackin.goswagger.io)
+
+[![license](http://img.shields.io/badge/license-Apache%20v2-orange.svg)](https://raw.githubusercontent.com/go-openapi/swag/master/LICENSE)
+[![GoDoc](https://godoc.org/github.com/go-openapi/swag?status.svg)](http://godoc.org/github.com/go-openapi/swag)
+[![GolangCI](https://golangci.com/badges/github.com/go-openapi/swag.svg)](https://golangci.com)
+[![Go Report Card](https://goreportcard.com/badge/github.com/go-openapi/swag)](https://goreportcard.com/report/github.com/go-openapi/swag)
+
+Contains a bunch of helper functions for go-openapi and go-swagger projects.
+
+You may also use it standalone for your projects.
+
+* convert between value and pointers for builtin types
+* convert from string to builtin types (wraps strconv)
+* fast json concatenation
+* search in path
+* load from file or http
+* name mangling
+
+
+This repo has only few dependencies outside of the standard library:
+
+* YAML utilities depend on gopkg.in/yaml.v2