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/client/node_remove.go

@@ -0,0 +1,21 @@
+package client
+
+import (
+	"net/url"
+
+	"github.com/docker/docker/api/types"
+
+	"golang.org/x/net/context"
+)
+
+// NodeRemove removes a Node.
+func (cli *Client) NodeRemove(ctx context.Context, nodeID string, options types.NodeRemoveOptions) error {
+	query := url.Values{}
+	if options.Force {
+		query.Set("force", "1")
+	}
+
+	resp, err := cli.delete(ctx, "/nodes/"+nodeID, query, nil)
+	ensureReaderClosed(resp)
+	return err
+}