Version 2.0.0

New Features:

• [color] New package for working with colors
• [usage] Added color tags support for description
• [strutil] Added method Fields for "smart" string splitting
• [system] Added method GroupList for user struct which return slice with user groups names

Improvements:

• [terminal] Improved reading y/n answers (incompatible changes)
• [system] Methods GetUsername and GetGroupname deprecated
• [jsonutil] Code refactoring
• [usage] Code refactoring
• Speeded up tests on Travis CI