Remove deprecated call to astropy helpers. (#554)

* Remove deprecated call to astropy helpers.

Closes #553

* Add the warnings-as-errors functionality via pytest options.

---------

Co-authored-by: P. L. Lim <2090236+pllim@users.noreply.github.com>

astroplan/tests/test_constraints.py

@@ -174,6 +174,8 @@ def test_galactic_plane_separation():
 
 # in astropy before v1.0.4, a recursion error is triggered by this test
 @pytest.mark.skipif('APY_LT104')
+# astropy.coordinates.errors.NonRotationTransformationWarning
+@pytest.mark.filterwarnings("ignore")
 def test_sun_separation():
     time = Time('2003-04-05 06:07:08')
     apo = Observer.at_site("APO")
@@ -198,6 +200,8 @@ def test_sun_separation():
     assert np.all(is_constraint_met == [False, True, True])
 
 
+# astropy.coordinates.errors.NonRotationTransformationWarning
+@pytest.mark.filterwarnings("ignore")
 def test_moon_separation():
     time = Time('2003-04-05 06:07:08')
     apo = Observer.at_site("APO")
@@ -423,6 +427,8 @@ def test_rescale_minmax():
 
 
 @pytest.mark.parametrize('constraint', constraint_tests)
+# astropy.coordinates.errors.NonRotationTransformationWarning
+@pytest.mark.filterwarnings("ignore")
 def test_regression_shapes(constraint):
     times = Time(["2015-08-28 03:30", "2015-09-05 10:30", "2015-09-15 18:35"])
     targets = get_skycoord([FixedTarget(SkyCoord(350.7*u.deg, 18.4*u.deg)),

setup.cfg

@@ -47,6 +47,14 @@ doctest_plus = enabled
 text_file_format = rst
 addopts = --doctest-rst --doctest-ignore-import-errors
 norecursedirs = build docs/_build
+filterwarnings =
+    error
+    ignore:numpy\.ndarray size changed:RuntimeWarning
+    ignore:numpy\.ufunc size changed:RuntimeWarning
+    # Can remove ignore when you bump astropy minversion high enough
+    ignore:distutils Version classes are deprecated:DeprecationWarning
+    # deprecated in Matplotlib 3.9 and will be removed in 3.11. Use plot instead.
+    ignore:The plot_date function was deprecated
 
 [coverage:run]
 omit =
@@ -88,4 +96,3 @@ max-line-length = 100
 [pycodestyle]
 exclude = _astropy_init.py,extern,__init__.py
 max-line-length = 100
-