Frontend test fix for spec-ci failures

[nthomas-mozilla]

Try specifying commander version

[nthomas-mozilla]

This is for bug 1481168. The back-end tests will be fixed by pull #731 .

[nthomas-mozilla]

@JohanLorenzo helped me track this down to the commander change tj/commander.js#778 using arrow functions, and our node is sufficiently old (0.10.mumble) that they're unsupported. If you hack up node_modules/lineman/tasks/spec-ci.coffee to show you stderr you get this with commander 2.17.0:

Running "spec-ci" task

/app/ui/node_modules/testem/node_modules/commander/index.js:663
    if (this._args.filter(a => a.required).length === 0) {
                             ^

We're planning to rewrite the UI this quarter so pinning commander is no worse than the current situation.

[JohanLorenzo]

I agree with this fix, for the time being.