Composer 2.0 Support

Adds support for Composer 2.0.

Minor Updates

• Cleaned up examples and README
• Support for quicksilver-script as well as quqicksilver-module
• Provide default path if none is set
• Compatibility with use in CircleCI

Quicksilver Composer Installer 1.0

Initial release with functionality for adding quicksilver-modules to a specified path based on settings in your composer.json file.