Release v2.0.0
Specification: #34
Changes:
- BREAKING: Remove 'commonjs' Command
- BREAKING: Remove 'cp' Command
- BREAKING: Remove 'rm' Command
- BREAKING: Remove 'util.expand()' and Fix 'clean'
- BREAKING: Remove 'package.readPackageJSON()'
- BREAKING: Rename 'util.fileExists()' to 'util.exists()'