add single dot host test

[pad01g]

I suspect Chrome and Firefox are not following the standard when the host is a single-byte . character and its non-special URL.

non-special:
https://jsdom.github.io/whatwg-url/#url=aDovLy4=&base=YWJvdXQ6Ymxhbms=

special:
https://jsdom.github.io/whatwg-url/#url=aHR0cDovLy4=&base=YWJvdXQ6Ymxhbms=

Related to jsdom/whatwg-url#82, jsdom/whatwg-url#245

By following https://url.spec.whatwg.org/# I think standard and implementation in this repository is correct and . should be returned.

This repository currently only has special test case.

wpt/url/resources/urltestdata.json

Lines 3889 to 3919 in 2a64dae

	"Domains with empty labels",
	{
	"input": "http://./",
	"base": "about:blank",
	"href": "http://./",
	"origin": "http://.",
	"protocol": "http:",
	"username": "",
	"password": "",
	"host": ".",
	"hostname": ".",
	"port": "",
	"pathname": "/",
	"search": "",
	"hash": ""
	},
	{
	"input": "http://../",
	"base": "about:blank",
	"href": "http://../",
	"origin": "http://..",
	"protocol": "http:",
	"username": "",
	"password": "",
	"host": "..",
	"hostname": "..",
	"port": "",
	"pathname": "/",
	"search": "",
	"hash": ""
	},

This PR adds test case for non-special URL.

[foolip]

Admin merged as requested by @annevk on Matrix.