Pig-lab: Solutions for: exercise 2-3

Signed-off-by: Enrico Canzonieri   	 <enrico.canzonieri@eurecom.fr>
Signed-off-by: Antonio Uccio Verardi     <antonio.verardi@eurecom.fr>
Folders refactoring

Signed-off-by: enrico canzonieri <enrico.canzonieri@eurecom.fr>
Merge pull request #3 from ecanzonieri/master

Pig-lab: Solutions for exercises 2-3