npm t never ends at /back-end dir

[KengoTODA]

When I run following commands in /back-end dir, it runs test but never ends.

$ nvm use
$ docker run -d --name taas-mongo --rm -p 27017:27017 mongo:3-jessie
$ cp config.yml.example config.yml
$ npm test
npm WARN [email protected] requires a peer of [email protected] - 4 but none is installed. You must install peer dependencies yourself.
npm WARN [email protected] No repository field.

up to date in 7.704s

> [email protected] test /path/to/test-automation-as-a-service/back-end
> NODE_ENV="test" nyc --reporter=html --reporter=text --report-dir=../reports/backend-coverage mocha test/*/ --delay --reporter mochawesome --reporter-options reportDir=../reports/backend-test,reportFilename=index; rm -rf .nyc_output

Read configurations from config.yml
Use /path/to/test-automation-as-a-service/back-end//var/log/taas for logging