Regularly and randomly failing resize test

[fieg]

The resize test is regularly and randomly failing on Travis CI:

infinite-ajax-scroll/test/resize_spec.js

Lines 15 to 29 in fa8f058

	it('should emit a resized event when resized', () => {
	const spy = {
	resized() {}
	};
	cy.spy(spy, 'resized');
	ias.on('resized', spy.resized);
	cy.viewport(320, 400);
	cy.wait(200).then(() => {
	expect(spy.resized).to.have.been.called;
	});
	});

Increasing the wait time might fix this issue.