Deprecation fixes

[Norgul]

Replaced deprecated curly braces, and added regex support for HTTP/2.

[bodva]

It would be great to have this merged.

cc @mnovozhylov

[mnovozhylov]

@bodva , please check https://github.com/upwork/php-upwork/blob/master/vendor-src/README.

[mnovozhylov]

@bodva , please check https://github.com/upwork/php-upwork/blob/master/vendor-src/README.

[Norgul]

@mnovozhylov unless it has a licence which prohibits changing (which defies the whole purpose of open source code), linking that readme and closing this PR made no sense whatsoever. You're literally declining having a non-breaking improvement merged.

[mnovozhylov]

@Norgul , I appreciate your feedback and engagement. I have to mention, still, that we do not maintain vendor's code. Instead, the library provides proper interface and the mentioned vendor library is just an example. You are free to organize your project in the proper way, and fork or update the vendor's code on your side.

[Norgul]

@mnovozhylov that all sounds reasonable, however vendor-src is a part of this repository and there is no package manager handling its dependencies.

Meaning unfortunately that even if I go and fork the package in question and make fixes there, it will do absolutely nothing with regards to this package working. I'm afraid that I'll keep using my branch until I find an alternative. Thanks anyway.

[bodva]

@mnovozhylov
Agree with @Norgul notice that the vendor-src is a part of this package because it is included here as a code directly, instead of dependencies.
It doesn't have the sense to link to the library because the library is outdated and looks like it does not have support anymore.

So for me, these two points mean you should maintain the code in the vendor-src the same way you maintain the code of the package itself.