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_config.go

@@ -0,0 +1,27 @@
+package project
+
+import (
+	"github.com/docker/libcompose/config"
+	"gopkg.in/yaml.v2"
+)
+
+// ExportedConfig holds config attribute that will be exported
+type ExportedConfig struct {
+	Version  string                           `yaml:"version,omitempty"`
+	Services map[string]*config.ServiceConfig `yaml:"services"`
+	Volumes  map[string]*config.VolumeConfig  `yaml:"volumes"`
+	Networks map[string]*config.NetworkConfig `yaml:"networks"`
+}
+
+// Config validates and print the compose file.
+func (p *Project) Config() (string, error) {
+	cfg := ExportedConfig{
+		Version:  "2.0",
+		Services: p.ServiceConfigs.All(),
+		Volumes:  p.VolumeConfigs,
+		Networks: p.NetworkConfigs,
+	}
+
+	bytes, err := yaml.Marshal(cfg)
+	return string(bytes), err
+}