See,
$ gometalinter --vendor --deadline 10m --disable-all --enable=golint ./...
ip.go:8:6⚠️ func SplitIpPort should be SplitIPPort (golint)
url.go:14:6⚠️ func NewUrlQueryReader should be NewURLQueryReader (golint)
url.go:9:6⚠️ type UrlQueryReader should be URLQueryReader (golint)
url.go:37:6⚠️ func JoinUrlFragments should be JoinURLFragments (golint)
The JoinUrlFragments function adds a trailing slash if to the proxy url
if the proxy path is an empty string. This fix removes that trailing
slash. Fixes#3847
