Update traefik dependencies (docker/docker and related) (#1823)

Update traefik dependencies (docker/docker and related)

- Update dependencies
- Fix compilation problems
- Remove vdemeester/docker-events (in docker api now)
- Remove `integration/vendor`
- Use `testImport`
- update some deps.
- regenerate the lock from scratch (after a `glide cc`)

vendor/github.com/docker/go-connections/sockets/sockets_unix.go

@@ -3,11 +3,31 @@
 package sockets
 
 import (
+	"fmt"
 	"net"
+	"net/http"
 	"syscall"
 	"time"
 )
 
+const maxUnixSocketPathSize = len(syscall.RawSockaddrUnix{}.Path)
+
+func configureUnixTransport(tr *http.Transport, proto, addr string) error {
+	if len(addr) > maxUnixSocketPathSize {
+		return fmt.Errorf("Unix socket path %q is too long", addr)
+	}
+	// No need for compression in local communications.
+	tr.DisableCompression = true
+	tr.Dial = func(_, _ string) (net.Conn, error) {
+		return net.DialTimeout(proto, addr, defaultTimeout)
+	}
+	return nil
+}
+
+func configureNpipeTransport(tr *http.Transport, proto, addr string) error {
+	return ErrProtocolNotAvailable
+}
+
 // DialPipe connects to a Windows named pipe.
 // This is not supported on other OSes.
 func DialPipe(_ string, _ time.Duration) (net.Conn, error) {