Allow interception of syncronous calls passing through this interceptor

Since we invoke the syncronous calls, we should allow catching of them.

This allows the user more flexibility in what their interceptor can do while maintaining the async interception functionality.

I understand you can create another interceptor, this just helps ensure a user can be flexible in their usage within the single interceptor.

Author: zach-snell

src/Ninject.Extensions.Interception/AsyncInterceptor.cs

@@ -23,8 +23,9 @@ public abstract class AsyncInterceptor : IInterceptor
         /// <summary>
         /// Intercepts the specified invocation.
         /// </summary>
+        /// <remarks>If overridden, you should invoke base.</remarks>
         /// <param name="invocation">The invocation to intercept.</param>
-        public void Intercept(IInvocation invocation)
+        public virtual void Intercept(IInvocation invocation)
         {
             var returnType = invocation.Request.Method.ReturnType;
             if (returnType == typeof(Task))