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/docker/registry/service_v2.go

@@ -0,0 +1,82 @@
+package registry
+
+import (
+	"net/url"
+	"strings"
+
+	"github.com/docker/go-connections/tlsconfig"
+)
+
+func (s *DefaultService) lookupV2Endpoints(hostname string) (endpoints []APIEndpoint, err error) {
+	tlsConfig := tlsconfig.ServerDefault()
+	if hostname == DefaultNamespace || hostname == IndexHostname {
+		// v2 mirrors
+		for _, mirror := range s.config.Mirrors {
+			if !strings.HasPrefix(mirror, "http://") && !strings.HasPrefix(mirror, "https://") {
+				mirror = "https://" + mirror
+			}
+			mirrorURL, err := url.Parse(mirror)
+			if err != nil {
+				return nil, err
+			}
+			mirrorTLSConfig, err := s.tlsConfigForMirror(mirrorURL)
+			if err != nil {
+				return nil, err
+			}
+			endpoints = append(endpoints, APIEndpoint{
+				URL: mirrorURL,
+				// guess mirrors are v2
+				Version:      APIVersion2,
+				Mirror:       true,
+				TrimHostname: true,
+				TLSConfig:    mirrorTLSConfig,
+			})
+		}
+		// v2 registry
+		endpoints = append(endpoints, APIEndpoint{
+			URL:          DefaultV2Registry,
+			Version:      APIVersion2,
+			Official:     true,
+			TrimHostname: true,
+			TLSConfig:    tlsConfig,
+		})
+
+		return endpoints, nil
+	}
+
+	ana := allowNondistributableArtifacts(s.config, hostname)
+
+	tlsConfig, err = s.tlsConfig(hostname)
+	if err != nil {
+		return nil, err
+	}
+
+	endpoints = []APIEndpoint{
+		{
+			URL: &url.URL{
+				Scheme: "https",
+				Host:   hostname,
+			},
+			Version: APIVersion2,
+			AllowNondistributableArtifacts: ana,
+			TrimHostname:                   true,
+			TLSConfig:                      tlsConfig,
+		},
+	}
+
+	if tlsConfig.InsecureSkipVerify {
+		endpoints = append(endpoints, APIEndpoint{
+			URL: &url.URL{
+				Scheme: "http",
+				Host:   hostname,
+			},
+			Version: APIVersion2,
+			AllowNondistributableArtifacts: ana,
+			TrimHostname:                   true,
+			// used to check if supposed to be secure via InsecureSkipVerify
+			TLSConfig: tlsConfig,
+		})
+	}
+
+	return endpoints, nil
+}