I use an old bootstrap theme in my ember app, how can I update it? How does ember plugin works?

I use this in my ember app : https://github.com/huxinghai1988/ember-adminlte-theme

But recently, it prevent me from building my app because of old dependencies. I forked it to try to repare it.

I tried the following to install it :

npm install bower install

The installation seems to be ok

WHen I try to run the server, here is the error message :

Error: Attempting to watch missing directory: /home/sylvain/dev/ember-adminlte-theme/node_modules/ember-adminlte-theme/vendor/
    at Watcher_addWatchDir [as addWatchDir] (/home/sylvain/dev/ember-adminlte-theme/node_modules/broccoli-sane-watcher/index.js:90:11)
    at /home/sylvain/dev/ember-adminlte-theme/node_modules/broccoli/lib/builder.js:94:35
    at tryCatch (/home/sylvain/dev/ember-adminlte-theme/node_modules/rsvp/dist/rsvp.js:525:12)
    at invokeCallback (/home/sylvain/dev/ember-adminlte-theme/node_modules/rsvp/dist/rsvp.js:538:13)
    at /home/sylvain/dev/ember-adminlte-theme/node_modules/rsvp/dist/rsvp.js:606:14
    at flush (/home/sylvain/dev/ember-adminlte-theme/node_modules/rsvp/dist/rsvp.js:2415:5)
    at process._tickCallback (internal/process/next_tick.js:61:11)

Like if he was looking for itself installed as a dependency.

How do I run the test on what seems to be an ember plugin that cannot be run alone?

How do I procede to migrate module from bower and then upgrade them?