export copy instruction types from index of just-scripts (#100)

* export copy instructions types as well

* change files

common/changes/just-scripts/types_2019-05-14-23-49.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "just-scripts",
+      "comment": "export copy instructions types as well",
+      "type": "patch"
+    }
+  ],
+  "packageName": "just-scripts",
+  "email": "kchau@microsoft.com"
+}

packages/just-scripts/src/index.ts

@@ -23,6 +23,7 @@ import webpackMerge from 'webpack-merge';
 export { webpackMerge };
 
 import * as copyInstructions from './copy/CopyInstruction';
+export { CopyInstruction, CopyConfig } from './copy/CopyInstruction';
 export { copyInstructions };
 
 export * from 'just-task';