Version 0.4.0

Version 0.4.0 of Mozart is here. The main change that everyone will notice is that Mozart now requires PHP 7.1 and up. The reasoning behind this is documented in #26, but the tldr is:

Mozart is a developers tool. In my humble opinion, developers should lead by example in using supported PHP versions only and have no reason to stay behind on unsupported versions.

Further changes in this release:

• Thanks to @kmgalanakis, we now have full Windows support, resolving an issue with the directory separator symbol. See #21 for more details.
• Thanks to @schlessera, we're now using modern versions of the Symfony components being used. With bumping the PHP version requirement, allowed me to make these new versions the only version we're using and making the version constraint more specific (only allowing ^4 now of both symfony/console and symfony/finder packages). See #25 for more details.
• I've fixed a bug where it would fail previously when trying to copy the same package to the new directory more than once. See #19 for more details.

Big thank you to everyone contributing to and using Mozart, your help is very much appreciated! 🎉