Skip slow tests unless --run-slow is specified.

`pytest --run-slow`

OR

`python3 setup.py test --args=--run-slow`

Author: mkelley

docs/install.rst

@@ -74,3 +74,15 @@ in order to use `sbpy` in your default Python environment. If you plan to work o
 .. code-block:: bash
 
     $ python setup.py develop --user
+
+
+Running tests
+^^^^^^^^^^^^^
+
+To verify your installation is properly working, run `sbpy`'s testing suite:
+
+.. code-block:: bash
+
+    $ python3 setpy.py test
+
+Add the `--remote-data` option to include tests that require a network connection, and `-args="--run-slow"` to include any slow tests.

sbpy/activity/gas/tests/test_prodrate_remote.py

@@ -59,6 +59,7 @@ def data_path(filename):
     return os.path.join(data_dir, filename)
 
 
+@pytest.mark.slow
 @remote_data
 def test_remote_prodrate_simple_hcn():
 
@@ -142,6 +143,7 @@ def test_remote_prodrate_simple_ch3oh():
     assert np.all(err < 0.35)
 
 
+@pytest.mark.slow
 @remote_data
 def test_einstein():
 

sbpy/conftest.py

@@ -2,6 +2,7 @@
 # by importing them here in conftest.py they are discoverable by py.test
 # no matter how it is invoked within the source tree.
 
+import pytest
 from astropy.version import version as astropy_version
 
 if astropy_version < '3.0':
@@ -15,8 +16,8 @@
     # variables that are used for configuration.
     from astropy.tests.plugins.display import PYTEST_HEADER_MODULES, TESTED_VERSIONS
 
-## Uncomment the following line to treat all DeprecationWarnings as
-## exceptions
+# Uncomment the following line to treat all DeprecationWarnings as
+# exceptions
 # enable_deprecations_as_exceptions()
 
 # Uncomment and customize the following lines to add/remove entries from
@@ -45,3 +46,26 @@
 packagename = os.path.basename(os.path.dirname(__file__))
 TESTED_VERSIONS[packagename] = version
 TESTED_VERSIONS['astropy_helpers'] = astropy_helpers_version
+
+
+# Add option to control run/skip of slow test (pytest.mark.slow)
+
+
+def pytest_addoption(parser):
+    parser.addoption(
+        "--run-slow", action="store_true", default=False, help="run slow tests"
+    )
+
+
+def pytest_configure(config):
+    config.addinivalue_line("markers", "slow: mark test as slow to run")
+
+
+def pytest_collection_modifyitems(config, items):
+    if config.getoption("--run-slow"):
+        # --run-slow given in cli: do not skip slow tests
+        return
+    skip_slow = pytest.mark.skip(reason="need --run-slow option to run")
+    for item in items:
+        if "slow" in item.keywords:
+            item.add_marker(skip_slow)