Bumped version to 0.3.1
Bumped version to 0.3.1

JoaoRodrigues/freesasa,JoaoRodrigues/freesasa,mittinatten/freesasa,mittinatten/freesasa,JoaoRodrigues/freesasa,JoaoRodrigues/freesasa,mittinatten/freesasa,mittinatten/freesasa