go.mod: update to github.com/emicklei/go-restful/v3 v3.7.3

full diff: https://github.com/emicklei/go-restful/compare/v2.9.5...v3.7.3

- Switch to using go modules
- Add check for wildcard to fix CORS filter
- Add check on writer to prevent compression of response twice
- Add OPTIONS shortcut WebService receiver
- Add Route metadata to request attributes or allow adding attributes to routes
- Add wroteHeader set
- Enable content encoding on Handle and ServeHTTP
- Feat: support google custom verb
- Feature: override list of method allowed without content-type
- Fix Allow header not set on '405: Method Not Allowed' responses
- Fix Go 1.15: conversion from int to string yields a string of one rune
- Fix WriteError return value
- Fix: use request/response resulting from filter chain
- handle path params with prefixes and suffixes
- HTTP response body was broken, if struct to be converted to JSON has boolean value
- List available representations in 406 body
- Support describing response headers
- Unwrap function in filter chain + remove unused dispatchWithFilters

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/emicklei/go-restful/v3/logger.go

@@ -0,0 +1,32 @@
+package restful
+
+// Copyright 2014 Ernest Micklei. All rights reserved.
+// Use of this source code is governed by a license
+// that can be found in the LICENSE file.
+import (
+	"github.com/emicklei/go-restful/v3/log"
+)
+
+var trace bool = false
+var traceLogger log.StdLogger
+
+func init() {
+	traceLogger = log.Logger // use the package logger by default
+}
+
+// TraceLogger enables detailed logging of Http request matching and filter invocation. Default no logger is set.
+// You may call EnableTracing() directly to enable trace logging to the package-wide logger.
+func TraceLogger(logger log.StdLogger) {
+	traceLogger = logger
+	EnableTracing(logger != nil)
+}
+
+// SetLogger exposes the setter for the global logger on the top-level package
+func SetLogger(customLogger log.StdLogger) {
+	log.SetLogger(customLogger)
+}
+
+// EnableTracing can be used to Trace logging on and off.
+func EnableTracing(enabled bool) {
+	trace = enabled
+}