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/libcompose/project/project_port.go

@@ -0,0 +1,26 @@
+package project
+
+import (
+	"fmt"
+
+	"golang.org/x/net/context"
+)
+
+// Port returns the public port for a port binding of the specified service.
+func (p *Project) Port(ctx context.Context, index int, protocol, serviceName, privatePort string) (string, error) {
+	service, err := p.CreateService(serviceName)
+	if err != nil {
+		return "", err
+	}
+
+	containers, err := service.Containers(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	if index < 1 || index > len(containers) {
+		return "", fmt.Errorf("Invalid index %d", index)
+	}
+
+	return containers[index-1].Port(ctx, fmt.Sprintf("%s/%s", privatePort, protocol))
+}