PHP artisan Undefined HTTP_USER_AGENT

I'm trying to add

        "mongodb/mongodb": ">=1.0.0",
        "jenssegers/mongodb": ">=3.0"

to my laravel 5.1 project and I get

  [ErrorException]
  Undefined index: HTTP_USER_AGENT

When I try to run php artisan I also get this error.

P.S. This is the first time I ever use php artisan by the way.