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/abbot/go-http-auth/users.go

@@ -6,11 +6,11 @@ import (
 	"sync"
 )
 
-/* 
+/*
  SecretProvider is used by authenticators. Takes user name and realm
  as an argument, returns secret required for authentication (HA1 for
  digest authentication, properly encrypted password for basic).
- 
+
  Returning an empty string means failing the authentication.
 */
 type SecretProvider func(user, realm string) string