Add test for the rolling_ball_options function

Author: ehrenfeu

tests/test_processing.py

@@ -0,0 +1,9 @@
+"""Tests for the imcflibs.imagej.processing module."""
+
+from imcflibs.imagej.processing import rolling_ball_options
+
+
+def test_rolling_ball_options():
+    """Test the rolling_ball_options function."""
+    options = rolling_ball_options(42.23)
+    assert options == "rolling=42.23"