Completes 1.3 exercise on Value

Signed-off-by: Irina Chichikova <diva.artim@gmail.com>
Completes 1.4 exercise on Value

Signed-off-by: Irina Chichikova <diva.artim@gmail.com>
Completes 1.5 exercise on Value

Signed-off-by: Irina Chichikova <diva.artim@gmail.com>
Completes 1.6 exercise on Value

Signed-off-by: Irina Chichikova <diva.artim@gmail.com>
Completes all Value exercises

Signed-off-by: Irina Chichikova <diva.artim@gmail.com>