DOC - add 'Raises' for seeds_from_mask and random_seeds_from_mask
DOC - add 'Raises' for seeds_from_mask and random_seeds_from_mask

jyeatman/dipy,nilgoyyou/dipy,FrancoisRheaultUS/dipy,jyeatman/dipy,matthieudumont/dipy,nilgoyyou/dipy,oesteban/dipy,StongeEtienne/dipy,villalonreina/dipy,oesteban/dipy,JohnGriffiths/dipy,rfdougherty/dipy,matthieudumont/dipy,sinkpoint/dipy,sinkpoint/dipy,StongeEtienne/dipy,villalonreina/dipy,demianw/dipy,demianw/dipy,FrancoisRheaultUS/dipy,rfdougherty/dipy,JohnGriffiths/dipy