Add new parameters to tests

Author: Bernarda Petek

test/test_bootplot.py

@@ -79,7 +79,7 @@ def test_bmp():
 def test_merge():
     np.random.seed(0)
     images = np.random.randint(low=0, high=256, size=(25, 100, 100, 3))
-    merged = merge_images(images)
+    merged = merge_images(images, k=2.5, threshold=0.3)
     assert merged.shape == (100, 100, 3)
     assert np.min(merged) >= 0
     assert np.max(merged) <= 255