Re-think integration vendoring

- remove docker/docker from  Traefik vendor (unused)
- use `ignore` for all Traefik vendor in integration glide.
- defined only integration specific version of the dependencies.

integration/vendor/github.com/Azure/go-ansiterm/parser.go

@@ -5,7 +5,7 @@ import (
 	"io/ioutil"
 	"os"
 
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 )
 
 var logger *logrus.Logger

integration/vendor/github.com/Azure/go-ansiterm/winterm/win_event_handler.go

@@ -9,7 +9,7 @@ import (
 	"strconv"
 
 	"github.com/Azure/go-ansiterm"
-	"github.com/Sirupsen/logrus"
+	"github.com/sirupsen/logrus"
 )
 
 var logger *logrus.Logger