July 4 (Reuters) - St Etienne striker Pierre-Emerick Aubameyang has signed a five-year deal with Borussia Dortmund, the Bundesliga club said on Thursday. No transfer fee was disclosed but media reports said it could be up to 13 million euros ($16.79 million). The 24-year-old Gabon international, who has won 33 caps, was the joint second highest scorer in Ligue 1 last season with 19 goals and helped St Etienne chalk up their first top-five finish in six years. ... More...