Upgrade vscode-test to fix regression #1138

see microsoft/vscode#84238

Signed-off-by: Aurélien Pupier <apupier@redhat.com>

Author: apupier

package-lock.json

@@ -553,7 +553,7 @@
     "tslint": "^5.11.0",
     "typescript": "^3.4.1",
     "typescript-tslint-plugin": "^0.3.1",
-    "vscode-test": "^1.0.0",
+    "vscode-test": "^1.2.3",
     "webpack": "^4.27.1",
     "webpack-cli": "^3.1.2",
     "lodash.template": ">=4.5.0"