Multi Project Validator

A tool which searches recursively for project.json files,
runs a set of analyses and reports on the result.

For CLI we have only one rule currently, that Dependencies
between projects must be equivalent to avoid stomping.

tools/MultiProjectValidator/IAnalysisRule.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.DotNet.ProjectModel;
+
+namespace MultiProjectValidator
+{
+    public interface IAnalysisRule
+    {
+        AnalysisResult Evaluate(List<ProjectContext> projectContexts);
+    }
+}