Add restore task

Author: Kapil Borle

.build.ps1

@@ -0,0 +1,14 @@
+param(
+    [ValidateSet("net451", "netstandard1.6")]
+    [string]$Framework = "netstandard1.6",
+
+    [ValidateSet("Debug", "Release", "PSv3Debug", "PSv3Release")]
+    [string]$Configuration = "Debug"
+)
+
+task -Name restore `
+    -Inputs Engine/project.json, Rules/project.json `
+    -Outputs Engine/project.lock.json, Rules/project.lock.json `
+    -Jobs {
+    dotnet restore
+}