feat(meta): IHasMeta interface

Author: jaredcnance

src/JsonApiDotNetCore/Models/IHasMeta.cs

@@ -0,0 +1,10 @@
+using System.Collections.Generic;
+using JsonApiDotNetCore.Services;
+
+namespace JsonApiDotNetCore.Models
+{
+    public interface IHasMeta
+    {
+        Dictionary<string, object> GetMeta(IJsonApiContext context);
+    }
+}