Adding support for custom attributes on rendered script and link tags

[weaverryan]

Fixes #10 - thanks to @dsech for the idea of relying on named Twig arguments (otherwise the new Twig attributes argument is the 4th argument... and rather inconvenient).

This can be configured in 3 different ways:

1) Globally

webpack_encore:
    # ...
    script_attributes:
        defer: true

2. when when using the Twig functions:

{{ encore_entry_script_tags('my_entry', attributes={
    defer: true
}) }}

3. Via a new RenderAssetTagEvent

As stated at the bottom of #10 - #10 (comment) - there may be some additional options that would also be nice, but this probably covers the biggest use-case.

NOTE: This also drops support for EOL Symfony versions.

Cheers!

[tgalopin]

You can probably bump to 7.2 as Symfony 4.4 requires it. This would allow you to remove a CI job too :)

[weaverryan]

I would love to - but I think 4.4 only requires 7.1 - https://github.com/symfony/skeleton/blob/1d596be50b63df6e8fdf94f89f7f38ae6d17e024/composer.json#L7

[tgalopin]

Ah indeed!

[nicodemuz]

@weaverryan is it possible to add attributes before the src attribute?

This is a requirement to disable Cloudflare Rocket Loader for a particular script, see:
https://support.cloudflare.com/hc/en-us/articles/200169436-How-can-I-have-Rocket-Loader-ignore-specific-JavaScripts-

The above link mentions The 'data-cfasync' attribute must be added before the 'src' attribute.:

<script data-cfasync="false" src="/javascript.js"></script>