test: do run with the "experimental" option required for Jest

Running Jest is no longer as easy as it used to be, thanks to the big
push for ECMAScript Modules.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

.vscode/launch.json

@@ -34,6 +34,7 @@
             "name": "Jest Debug Current File",
             "type": "node",
             "request": "launch",
+            "runtimeArgs": [ "--experimental-vm-modules" ],
             "program": "${workspaceFolder}/node_modules/jest/bin/jest.js",
             "args": [
                 "--runInBand",