Move constructor type tests into a single test

packages/keyv/test/unit.js

@@ -1,11 +1,8 @@
 import test from 'ava';
 import Keyv from '../';
 
-test('Keyv is a function', t => {
+test('Keyv is a class', t => {
 	t.is(typeof Keyv, 'function');
-});
-
-test('Keyv cannot be invoked without \'new\'', t => {
 	t.throws(() => Keyv()); // eslint-disable-line new-cap
 	t.notThrows(() => new Keyv());
 });