TP3 flatmap



Signed-off-by: MEHRANI ARDALAN <3402426@ari-31-207-01.ufr-info-p6.jussieu.fr>
Merge branch 'master' of https://github.com/morpheushoc/Data_Science_School.git
building similarity from sparse matrix

Signed-off-by: MEHRANI ARDALAN <3402426@ari-31-207-15.ufr-info-p6.jussieu.fr>