fix CI failure

[AkihiroSuda]

Signed-off-by: Akihiro Suda suda.akihiro@lab.ntt.co.jp

suda@ws01:~/gopath/src/github.com/docker/go-connections⟫ go vet ./...    
tlsconfig/config_test.go:304: no formatting directive in Fatalf call     
tlsconfig/config_test.go:323: no formatting directive in Fatalf call     
exit status 1                       
1 suda@ws01:~/gopath/src/github.com/docker/go-connections⟫ test -z "$(golint ./... | tee /dev/stderr)"                                            
nat/parse.go:36:27: error strings should not be capitalized or end with punctuation or a newline                                                  
tlsconfig/config.go:240:26: error strings should not be capitalized or end with punctuation or a newline                                          
1 suda@ws01:~/gopath/src/github.com/docker/go-connections⟫ test -z "$(gofmt -s -l . | tee /dev/stderr)"                                           
proxy/udp_proxy.go                  
tlsconfig/certpool_other.go         
1 suda@ws01:~/gopath/src/github.com/docker/go-connections⟫ 

[vdemeester]

LGTM 🌮