Change version number to 1.0.15

ltfatpy/tests/comp/test_comp_gabdual.py

ltfatpy/tests/comp/test_comp_hermite.py

ltfatpy/tests/comp/test_comp_hermite_all.py

ltfatpy/tests/comp/test_comp_isepdgt.py

ltfatpy/tests/comp/test_comp_pgauss.py

ltfatpy/tests/comp/test_comp_sepdgt.py

ltfatpy/tests/comp/test_comp_sigreshape.py

ltfatpy/tests/datasets/get_dataset_path.py

ltfatpy/tests/datasets/read_comp_dct_signal_ex_mat.py

ltfatpy/tests/datasets/read_comp_dst_signal_ex_mat.py

ltfatpy/tests/datasets/read_dgt_signal_ex_mat.py

ltfatpy/tests/datasets/read_gabframediag_signal_ex_mat.py

ltfatpy/tests/datasets/read_gabtight_signal_ex_mat.py

ltfatpy/tests/datasets/read_ref_mat.py

ltfatpy/tests/datasets/read_s0norm_ex_mat.py

ltfatpy/tests/datasets/test_read_dgt_signal_ext.py

ltfatpy/tests/datasets/test_read_ref_mat.py

ltfatpy/tests/fourier/test_dct.py

ltfatpy/tests/fourier/test_dft.py

ltfatpy/tests/fourier/test_dst.py