Resolve "Image creation bugs with 0 size windows"

Closes #21 (closed)

skais/tests/utils/test_geometry.py

+import unittest
+
+from skais.utils.geometry import bresenham
+
+
+class TestGeometry(unittest.TestCase):
+    def test_bresenham(self):
+        result = bresenham(3, 4, 16, 9)
+        expected = [(3, 4), (4, 4), (5, 5), (6, 5), (7, 6), (8, 6), (9, 6), (10, 7), (11, 7), (12, 7), (13, 8), (14, 8),
+                    (15, 9), (16, 9)]
+
+        self.assertListEqual(result, expected)
+
+    def test_bresenham_inverted(self):
+        result = bresenham(16, 9, 3, 4)
+        expected = [(3, 4), (4, 4), (5, 5), (6, 5), (7, 6), (8, 6), (9, 6), (10, 7), (11, 7), (12, 7), (13, 8),
+                    (14, 8), (15, 9), (16, 9)]
+
+        self.assertListEqual(result, expected)
+
+    def test_bresenham_same_line(self):
+        result = bresenham(3, 4, 10, 4)
+        expected = [(3, 4), (4, 4), (5, 4), (6, 4), (7, 4), (8, 4), (9, 4), (10, 4)]
+
+        self.assertListEqual(result, expected)
+
+    def test_bresenham_same_column(self):
+        result = bresenham(3, 4, 3, 10)
+        expected = [(3, 4), (3, 5), (3, 6), (3, 7), (3, 8), (3, 9), (3, 10)]
+
+        self.assertListEqual(result, expected)
+
+
+if __name__ == '__main__':
+    unittest.main()