0.15.0

Hello again. With this release, Studio is finally compatible with Composer 2.

Also, please welcome @apfelbox as an additional maintainer! 🙌

Summary

• Drop support for PHP <7.
• Add support for Composer 2 (#101, #104 by @emodric).
• Add support for Symfony 5.0 (#98, #102 and #106 by @emodric and @apfelbox).
• When using create to clone packages, additional Git options can be provided (#93 by @gnutix).
• Deduplicate entries in studio.json (#94 and #103 by @gnutix and @apfelbox).