Revert to using gulp for build

Author: elenatanasoiu

extensions/ql-vscode/package.json

@@ -1121,7 +1121,7 @@
     "watch:webpack": "gulp watchView",
     "watch:css": "gulp watchCss",
     "test": "mocha --exit -r ts-node/register test/pure-tests/**/*.ts",
-    "preintegration": "rm -rf ./out/vscode-tests && npm run build",
+    "preintegration": "rm -rf ./out/vscode-tests && gulp",
     "integration": "node ./out/vscode-tests/run-integration-tests.js no-workspace,minimal-workspace",
     "cli-integration": "npm run preintegration && node ./out/vscode-tests/run-integration-tests.js cli-integration",
     "update-vscode": "node ./node_modules/vscode/bin/install",