optimizing badger cache, won a 10-15% improvement in most benchmarks

pkg/dgraph/utils.go

@@ -0,0 +1,10 @@
+package dgraph
+
+import (
+	"encoding/json"
+)
+
+// unmarshalJSON is a helper to unmarshal JSON with error handling
+func unmarshalJSON(data []byte, v interface{}) error {
+	return json.Unmarshal(data, v)
+}