Add Laravel Octane Support

[mcolominas]

Responding to a thread on laravel/octane (laravel/octane#551 (comment)), I discovered a bug in this package.

From what I indicate in the title, this package is not supported when using Laravel Octane.

• What is the problem?
  When updating the language of the application using app()->setLocale('xx'), the language in carbon is not updated

• Where does the problem originate?
  In:
  

  Carbon/src/Carbon/Laravel/ServiceProvider.php

  Line 47 in a900060

  $app = $this->app && method_exists($this->app, 'getLocale') ? $this->app : app('translator');

  
  Gets the application from when laravel octane is instantiated, so even if the language is changed, it will continue to return the default language, causing carbon to not update.

• How to solve the problem?
  Change the $this->app inside updateLocale

  Carbon/src/Carbon/Laravel/ServiceProvider.php

  Line 45 in a900060

  public function updateLocale()

  
  to Illuminate\Container\Container::getInstance()

This solution should work whether laravel octane is used or not.

[kylekatarnls]

We'll try to work around this issue, but this is a global pitfall for any laravel service provider, it should instead be fixed in https://github.com/laravel/octane/blob/1.x/src/CurrentApplication.php#L25 IMO where Octane could change the app for each provider.

[kylekatarnls]

I proposed instead a global fix in laravel/octane for any provider doing similar boot process: laravel/octane#556