We are checking `Gemfile.lock`, so the gem name will be bare; e.g.,

```
bash-4.2$ grep rails Gemfile.lock
    coffee-rails (3.2.2)
    jquery-rails (2.2.1)
    rails (3.2.13)
    sass-rails (3.2.6)
  coffee-rails (~> 3.2.1)
  jquery-rails
  rails (~> 3.2.13)
  sass-rails (~> 3.2.3)
```