Add back the LWC tests

packages/salesforcedx-vscode-lwc/package.json

@@ -47,7 +47,10 @@
     "watch": "tsc -watch -p .",
     "clean":
       "shx rm -rf node_modules && shx rm -rf out && shx rm -rf coverage && shx rm -rf .nyc_output",
-    "postinstall": "node ./node_modules/vscode/bin/install"
+    "postinstall": "node ./node_modules/vscode/bin/install",
+    "pretest": "node ../../scripts/download-vscode-for-system-tests",
+    "test":
+      "node ../../scripts/install-vsix-dependencies dbaeumer.vscode-eslint && node ../../scripts/run-test-with-top-level-extensions"
   },
   "activationEvents": [
     "workspaceContains:package.json",