[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/github.com/json-iterator/go/go.mod b/vendor/github.com/json-iterator/go/go.mod
new file mode 100644
index 0000000..e05c42f
--- /dev/null
+++ b/vendor/github.com/json-iterator/go/go.mod
@@ -0,0 +1,11 @@
+module github.com/json-iterator/go
+
+go 1.12
+
+require (
+	github.com/davecgh/go-spew v1.1.1
+	github.com/google/gofuzz v1.0.0
+	github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421
+	github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742
+	github.com/stretchr/testify v1.3.0
+)