Move generator code in a singleton
Add first unit test
Parameter 'size' in generateBlocks doesn't need substract
Update README.md

Add Build Status Image
Rename NainConstants to Constants
Remove test in desktop module (nothing to test)
Improve test
- Improve javadoc
- Use parallelStream() instead stream().parallel()
- Fix typo
Add coveralls support
change gradle to gradlew
add Coveralls badge
merge README.md