add vendoring with go dep

vendor/github.com/influxdata/influxdb/tsdb/cursor.go

@@ -0,0 +1,13 @@
+package tsdb
+
+import "github.com/influxdata/influxdb/influxql"
+
+// EOF represents a "not found" key returned by a Cursor.
+const EOF = influxql.ZeroTime
+
+// Cursor represents an iterator over a series.
+type Cursor interface {
+	SeekTo(seek int64) (key int64, value interface{})
+	Next() (key int64, value interface{})
+	Ascending() bool
+}