Update tests scripts for data module

tests/test_data.py

@@ -1,6 +1,6 @@
 import pytest
 import pandas as pd
-from pynssp import load_simulated_ts, get_scenario1, get_scenario2
+from pynssp import load_simulated_ts, get_scenario1, get_scenario2, load_nssp_stopwords
 
 
 @pytest.fixture
@@ -18,6 +18,11 @@ def scenario2():
     return get_scenario2()
 
 
+@pytest.fixture
+def nssp_stopwords():
+    return load_nssp_stopwords()
+
+
 def test_load_simulated_ts(simulated_ts):
     assert isinstance(simulated_ts, pd.DataFrame)
     assert len(simulated_ts) == 626
@@ -34,3 +39,9 @@ def test_get_scenario2(scenario2):
     assert isinstance(scenario2, pd.DataFrame)
     assert len(scenario2) == 313
     assert len(scenario2.columns) == 6
+
+
+def test_load_nssp_stopwords(nssp_stopwords):
+    assert isinstance(nssp_stopwords, pd.DataFrame)
+    assert len(nssp_stopwords) == 835
+    assert len(nssp_stopwords.columns) == 2