Add vendoring to containerd master

Initial vendor list validated with empty $GOPATH
and only master checked out; followed by `make`
and verified that all binaries build properly.
Updates require github.com/LK4D4/vndr tool.

Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>

vendor/github.com/stevvooe/go-btrfs/info.go

@@ -0,0 +1,29 @@
+package btrfs
+
+// Info describes metadata about a btrfs subvolume.
+type Info struct {
+	ID         uint64 // subvolume id
+	ParentID   uint64 // aka ref_tree
+	TopLevelID uint64 // not actually clear what this is, not set for now.
+	Offset     uint64 // key offset for root
+	DirID      uint64
+
+	Generation         uint64
+	OriginalGeneration uint64
+
+	UUID         string
+	ParentUUID   string
+	ReceivedUUID string
+
+	Name string
+	Path string // absolute path of subvolume
+	Root string // path of root mount point
+
+	Readonly bool // true if the snaps hot is readonly, extracted from flags
+}
+
+type infosByID []Info
+
+func (b infosByID) Len() int           { return len(b) }
+func (b infosByID) Less(i, j int) bool { return b[i].ID < b[j].ID }
+func (b infosByID) Swap(i, j int)      { b[i], b[j] = b[j], b[i] }