Add missing testify/mock

Godeps/_workspace/src/github.com/stretchr/objx/value.go

@@ -0,0 +1,13 @@
+package objx
+
+// Value provides methods for extracting interface{} data in various
+// types.
+type Value struct {
+	// data contains the raw data being managed by this Value
+	data interface{}
+}
+
+// Data returns the raw data contained by this Value
+func (v *Value) Data() interface{} {
+	return v.data
+}