container file tweaks

[plutopulp]

Allow for file.urls and fixes a bug with file url parsing.

[plutopulp]

What was the bug this was trying to fix out of interest?

Also, if we no longer need the validators package could you remove it from poetry and also from pipeline/container/docker_templates/dockerfile_template.txt?

Yeah good shout, have removed the validators package as doesn't seemed to be used anymore. As discussed, originally we had:

 if validators.url(path_or_url):
            url = str(urllib.parse.urlparse(path_or_url).geturl())

But it doesn't return a bool when it fails, but an error object, e.g.:

>>> validators.url("abc@email.com")
ValidationError(func=url, args={'value': 'abc@email.com'})