Replace file_get_contents() with symfony/http-client

[Toflar]

Hey Samuel,

Great work, I really enjoy this tool!

As it is already using Symfony components, I was wondering if you would be okay with replacing FileGetContents by the Symfony HttpClient. We'd have numerous advantages:

• Proper exception handling
• Support for cURL with auto-fallback to fopen/file_get_contents
• Loads of quirks dealt with for us
• etc.

Just checking before I create a PR :)

[gordalina]

I'd happily accept a PR with a new SymfonyHttpClient adapter. You'd have more control on how to have the adapter configured as well.
Changing the current FileGetContents adapter could lead to breaking changes for current users. 👍