1.6.0-RC - released 2017-12-19

Changelog

Improved performance of installs and updates from git clones when checking out known commits
Added check-platform-reqs command that checks that your PHP and extensions versions match the platform requirements of the installed packages
Added --with-all-dependencies to the update and require commands which updates all dependencies of the listed packages, including those that are direct root requirements
Added scripts-descriptions key to composer.json to customize the description and document your custom commands
Added support for the uppercase NO_PROXY env var
Added support for COMPOSERDEFAULT{AUTHOR,LICENSE,EMAIL,VENDOR} env vars to pre-populate init command values
Added support for local fossil repositories
Added suggestions for alternative spellings when entering packages in init and require commands and nothing can be found
Fixed installed.json data to be sorted alphabetically by package name
Fixed compatibility with Symfony 4.x components that Composer uses