* St Etienne fifth after 3-0 win at Nancy * Six goals in five games for Aubameyang (Adds quotes) PARIS, Feb 23 (Reuters) - In-form striker Pierre-Emerick Aubameyang scored twice to help St Etienne beat Ligue 1 bottom club Nancy 3-0 on Saturday to close the gap on fourth-placed Nice to one point. Fellow attacker Brandao put the visitors ahead in the 17th minute from a neat Renaud Cohade cross and Aubameyang made it 2-0 with a curling low shot five minutes before the break. Aubameyang's sixth goal in five games - his 14th in the league this season - then sealed victory with two minutes to go. ... More...