Added describe to test_15

test/test_15.js

 import multiplyNumeric from "../solution_15.js";
 import assert from "assert";
 
+describe("\n\nSolution_15", () => {
   it("should return the correct object", () => {
     let initial = {
       width: 200,
@@ -24,3 +25,4 @@ it("should return the correct object", () => {
     assert.equal(dbl2.b, 2 * second.b);
     assert.equal(dbl2.c, second.c);
   });
+});
\ No newline at end of file