merge: EuclidGCD: add tests (TheAlgorithms#994)

test was not present beforehand.

Author: merelymyself

Maths/test/GetEuclidGCD.test.js

@@ -0,0 +1,12 @@
+import { GetEuclidGCD } from '../GetEuclidGCD'
+
+function testEuclidGCD (n, m, expected) {
+  test('Testing on ' + n + ' and ' + m + '!', () => {
+    expect(GetEuclidGCD(n, m)).toBe(expected)
+  })
+}
+
+testEuclidGCD(5, 20, 5)
+testEuclidGCD(109, 902, 1)
+testEuclidGCD(290, 780, 10)
+testEuclidGCD(104, 156, 52)