add test for the program script calculate_optimal_voltages used in main

tests/program_test.py

@@ -0,0 +1,16 @@
+import numpy as np
+import pytest
+
+from bimorph_mirror_analysis.__main__ import calculate_optimal_voltages
+
+
+@pytest.mark.parametrize(
+    ["input_file", "expected_voltages"],
+    [["tests/data/raw_data.csv", np.array([72.14, 50.98, 18.59])]],
+)
+def test_calculate_optimal_voltages(
+    input_file: str, expected_voltages: np.typing.NDArray[np.float64]
+):
+    voltages = calculate_optimal_voltages(input_file)
+    voltages = np.round(voltages, 2)
+    np.testing.assert_almost_equal(voltages, expected_voltages)