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/docker/ctx/context.go

@@ -0,0 +1,35 @@
+package ctx
+
+import (
+	cliconfig "github.com/docker/cli/cli/config"
+	"github.com/docker/cli/cli/config/configfile"
+	"github.com/docker/libcompose/docker/auth"
+	"github.com/docker/libcompose/docker/client"
+	"github.com/docker/libcompose/project"
+)
+
+// Context holds context meta information about a libcompose project and docker
+// client information (like configuration file, builder to use, …)
+type Context struct {
+	project.Context
+	ClientFactory client.Factory
+	ConfigDir     string
+	ConfigFile    *configfile.ConfigFile
+	AuthLookup    auth.Lookup
+}
+
+// LookupConfig tries to load the docker configuration files, if any.
+func (c *Context) LookupConfig() error {
+	if c.ConfigFile != nil {
+		return nil
+	}
+
+	config, err := cliconfig.Load(c.ConfigDir)
+	if err != nil {
+		return err
+	}
+
+	c.ConfigFile = config
+
+	return nil
+}