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>

integration/client/go.sum

@@ -201,6 +201,7 @@ github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25Kn
 github.com/elazarl/goproxy v0.0.0-20180725130230-947c36da3153/go.mod h1:/Zj4wYkgs4iZTTu3o/KG3Itv/qCCa8VVMlb3i9OVuzc=
 github.com/emicklei/go-restful v0.0.0-20170410110728-ff4f55a20633/go.mod h1:otzb+WCGbkyDHkqmQmT5YD2WR4BBwUdeQoFo8l/7tVs=
 github.com/emicklei/go-restful v2.9.5+incompatible/go.mod h1:otzb+WCGbkyDHkqmQmT5YD2WR4BBwUdeQoFo8l/7tVs=
+github.com/emicklei/go-restful/v3 v3.7.3/go.mod h1:6n3XBCmQQb25CM2LCACGz8ukIrRry+4bhvbpWn3mrbc=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=