Feature/update least common multiple (#1352)

* renamed module to extend the acronym

* add type hints (will not work with Python less than 3.4)

* update docstring

* refactor the function

* add unittests for the least common squares multiple

maths/least_common_multiple.py

@@ -0,0 +1,44 @@
+import unittest
+
+
+def find_lcm(first_num: int, second_num: int) -> int:
+    """Find the least common multiple of two numbers.
+
+       Learn more: https://en.wikipedia.org/wiki/Least_common_multiple
+
+       >>> find_lcm(5,2)
+       10
+       >>> find_lcm(12,76)
+       228
+    """
+    max_num = first_num if first_num >= second_num else second_num
+    common_mult = max_num
+    while (common_mult % first_num > 0) or (common_mult % second_num > 0):
+        common_mult += max_num
+    return common_mult
+
+
+class TestLeastCommonMultiple(unittest.TestCase):
+
+    test_inputs = [
+        (10, 20),
+        (13, 15),
+        (4, 31),
+        (10, 42),
+        (43, 34),
+        (5, 12),
+        (12, 25),
+        (10, 25),
+        (6, 9),
+    ]
+    expected_results = [20, 195, 124, 210, 1462, 60, 300, 50, 18]
+
+    def test_lcm_function(self):
+        for i, (first_num, second_num) in enumerate(self.test_inputs):
+            actual_result = find_lcm(first_num, second_num)
+            with self.subTest(i=i):
+                self.assertEqual(actual_result, self.expected_results[i])
+
+
+if __name__ == "__main__":
+    unittest.main()