Fix: relative symlinks for Drupal profiles (due to a double /)

Also fixes a warning about a missing app/config dir, for plain
composer.json projects.
Update README.md
Fix: environments cache emptied by drush-aliases command.
Allow the user to modify aliases without overwriting their changes.
Allow the CLI to auto-delete aliases for deleted environments.
Tag v1.2.2
Fix branch --build option
Run other commands using the recommended method.
Fix- EnvironmentCommand::validateInput() caused CurlException.
Release v1.2.3
Improve error output from Platform.sh API calls.
Add the URL to the exception messsage.
Placate IDEs
No need to involve PHP to read an environment variable.
Reload environments after deactivate.
Tweak delete message for consistency.
Release v1.2.4
Fix 'Array must contain at least one element' in checkout.
Merge branch 'issue/150/improve-error-output' into development
Force absolute links on Windows.