Remove dependency on nosetests

[AlexanderFabisch]

Will be replaced by pytest in the future

pytransform3d/test/test_urdf.py
15:from nose.tools import assert_raises, assert_equal, assert_true, assert_in
16:from nose import SkipTest

pytransform3d/test/test_transformations.py
33:from nose.tools import (assert_equal, assert_almost_equal,

pytransform3d/test/test_rotations.py
4:from nose.tools import (assert_almost_equal, assert_equal, assert_true,

pytransform3d/test/test_transform_manager.py
15:from nose.tools import (assert_raises_regexp, assert_equal, assert_true,
17:from nose import SkipTest

pytransform3d/test/test_coordinates.py
3:from nose.tools import assert_less_equal

pytransform3d/test/test_camera.py
6:from nose.tools import (assert_raises_regexp, assert_false, assert_in,

pytransform3d/test/test_batch_rotations.py
4:from nose.tools import (assert_almost_equal, assert_raises_regexp,

pytransform3d/test/test_plot_utils.py
2:from nose import SkipTest
11:from nose.tools import assert_equal, assert_less, assert_greater_equal

pytransform3d/transformations/_testing.py
109:    This function needs the dependency nose.
149:    from nose.tools import assert_almost_equal