Test cleanup and fixes [c-d]

test/similarity/similarity.test.js

@@ -5,5 +5,7 @@ const similarity = require('./similarity.js');
   test('similarity is a Function', () => {
   expect(similarity).toBeInstanceOf(Function);
 });
-  t.deepEqual(similarity([1, 2, 3], [1, 2, 4]), [1, 2], "Returns an array of elements that appear in both arrays.");
+  test('Returns an array of elements that appear in both arrays.', () => {
+  expect(similarity([1, 2, 3], [1, 2, 4]), [1).toEqual(2])
+});