update build scripts

Author: sandorfr

package.json

@@ -39,7 +39,7 @@
     "@types/node": "^6.0.0",
     "@types/q": "^1.0.3",
     "async": "2.0.1",
-    "gl-vsts-tasks-build-scripts": "0.4.0-alpha.2",
+    "gl-vsts-tasks-build-scripts": "0.4.0-alpha.4",
     "karma": "^1.1.2",
     "npm-run-all": "2.3.0",
     "tslint": "5.7.0",