Improve error output from Platform.sh API calls.
Add the URL to the exception messsage.
Fix 'Array must contain at least one element' in checkout.
Merge branch 'issue/150/improve-error-output' into development
Force absolute links on Windows.
Use rmdir() instead of unlink() to delete www in Windows.
Clarify that the Composer vendor/bin directory command does not apply to Windows.
Only rmdir dirs.
Merge pull request #156 from pjcdawkins/windows-abslinks

Improve symlinks on Windows
Make project:clean report number of kept builds.
Release v1.2.5
Release v1.2.6 only to fix the version numbering.
Fix invalid argument for foreach() in relationships command when offline.

Also removes uncaught exceptions when offline for environment commands.
Don't cache an empty list of environments.
Refactor filesystem, Drush, shell utilities.
Fix drush aliases writability check
Convert Drush class to a console helper
Start automated tests
Test FilesystemHelper.
Use the Symfony Filesystem component