TUN-3403: Unit test for origin/proxy to test serving HTTP and Websocket

vendor/github.com/gobwas/httphead/README.md

@@ -0,0 +1,63 @@
+# httphead.[go](https://golang.org)
+
+[![GoDoc][godoc-image]][godoc-url] 
+
+> Tiny HTTP header value parsing library in go.
+
+## Overview
+
+This library contains low-level functions for scanning HTTP RFC2616 compatible header value grammars.
+
+## Install
+
+```shell
+    go get github.com/gobwas/httphead
+```
+
+## Example
+
+The example below shows how multiple-choise HTTP header value could be parsed with this library:
+
+```go
+	options, ok := httphead.ParseOptions([]byte(`foo;bar=1,baz`), nil)
+	fmt.Println(options, ok)
+	// Output: [{foo map[bar:1]} {baz map[]}] true
+```
+
+The low-level example below shows how to optimize keys skipping and selection
+of some key:
+
+```go
+	// The right part of full header line like:
+	// X-My-Header: key;foo=bar;baz,key;baz
+	header := []byte(`foo;a=0,foo;a=1,foo;a=2,foo;a=3`)
+
+	// We want to search key "foo" with an "a" parameter that equal to "2".
+	var (
+		foo = []byte(`foo`)
+		a   = []byte(`a`)
+		v   = []byte(`2`)
+	)
+	var found bool
+	httphead.ScanOptions(header, func(i int, key, param, value []byte) Control {
+		if !bytes.Equal(key, foo) {
+			return ControlSkip
+		}
+		if !bytes.Equal(param, a) {
+			if bytes.Equal(value, v) {
+				// Found it!
+				found = true
+				return ControlBreak
+			}
+			return ControlSkip
+		}
+		return ControlContinue
+	})
+```
+
+For more usage examples please see [docs][godoc-url] or package tests.
+
+[godoc-image]: https://godoc.org/github.com/gobwas/httphead?status.svg
+[godoc-url]: https://godoc.org/github.com/gobwas/httphead
+[travis-image]: https://travis-ci.org/gobwas/httphead.svg?branch=master
+[travis-url]: https://travis-ci.org/gobwas/httphead