Create task to parse json files

src/core-sdk-tasks/JsonPropertyParser.cs

@@ -0,0 +1,54 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+using Newtonsoft.Json.Linq;
+
+namespace Microsoft.DotNet.Cli.Build
+{
+    public class JsonPropertyParser : Task
+    {
+        [Required]
+        public string Filename
+        {
+            get;
+            set;
+        }
+
+        [Required]
+        public string Path
+        {
+            get;
+            set;
+        }
+
+        [Output]
+        public string Value
+        {
+            get;
+            private set;
+        }
+
+        public override bool Execute()
+        {
+            try
+            {
+                using (var sr = new StreamReader(Filename))
+                {
+                    var json = sr.ReadToEnd();
+                    var o = JObject.Parse(json);
+                    Value = o.SelectToken(Path).Value<string>();
+                }
+            }
+            catch (Exception e)
+            {
+                Log.LogErrorFromException(e);
+            }
+
+            return !Log.HasLoggedErrors;
+        }
+    }
+}