created a plugin for schema validation and related unit test

plugins/plugin.go

@@ -0,0 +1,11 @@
+package main
+
+import "context"
+
+type Validator interface {
+	Validate(ctx context.Context, b []byte) error //context parameter
+}
+
+type ValidatorProvider interface {
+	New(p string) (Validator, error)
+}