Allow regexes in t.like

[tommy-mitchell]

The message property in t.throws is really ergonomic - it can be a string, RegExp, or even a function. t.like should be just as ergonomic with strings:

const output = foo();

t.like(output, {
  name: 'foo',
  source: /foo comes from/,
});

---

A motivating example is trying to convert this test from npm-user to use t.like:

const user = await npmUser('sindresorhus');

t.like(user, {
	name: 'Sindre Sorhus',
	avatar: /npm-avatar/,
	email: 'sindresorhus@gmail.com',
});

[novemberborn]

Currently like is a partial deepEqual, selecting from the actual (first argument) just those properties that exist in the expected (second argument). How would we do that if expected contains a regular expression value?