Currently, `ENV["SELENIUM_HOST"]` is evaluated when generating a file. So
the result was the following.
```
driven_by :selenium, using: :headless_chrome, screen_size: [ 1400, 1400 ], options: {
browser: :remote,
url: "http://:4444"
}
```
This PR fixes to output the URL setting just as a string. The after
result is the following.
```
driven_by :selenium, using: :headless_chrome, screen_size: [ 1400, 1400 ], options: {
browser: :remote,
url: "http://#{ENV["SELENIUM_HOST"]}:4444"
}
```
44a64ce904