Correctly set up directory path to input data to correctly work withi…

…n a GHA or for running locally

test/test_mode_2d_statistics.py

@@ -1,18 +1,25 @@
+
+import os
 import pytest
 import numpy as np
 import pandas as pd
 
 import metcalcpy.util.mode_2d_ratio_statistics as m2rs
 import metcalcpy.util.mode_2d_arearat_statistics as m2as
 
+
+cwd = os.path.dirname(__file__)
+
 def prepare_data(obj_type = "2d"):
     """
     Prepare some data for testing mode ara rations.
     This uses an existing file in test/data. A more 
     robust approach would be to use a real MODE export
     from METviewer.
     """
-    file_path = "test/data/ee_av_input.data"
+    os.environ['TEST_DIR'] = cwd
+
+    file_path = f"{cwd}/data/ee_av_input.data"
     df = pd.read_csv(file_path, sep="\t")
 
     df["object_type"] = obj_type