identify github username from urls like http://shinnn.github.io

[balupton]

places where duplicate contributors have popped up:

• bevry/istextorbinary@f43983a
• automate removal of duplicates in contributing section staticsitegenerators-list#418

updating fellow, which is used by projectz to dedupe fetched contributors, to support githubUsername.github.io url patterns would solve this source of duplication

the necessary change would be here — the regexp would be updated to support both the username.github.io format and the github.com/username format, and adding support for gist.github.com/username would be great too — with a test needing to be created for it as well:

fellow/source/index.ts

Lines 313 to 318 in 9d1bca6

	// github
	const githubMatch = /^.+github.com\/([^/]+)\/?$/.exec(input)
	if (githubMatch) {
	this.githubUsername = githubMatch[1]
	url = this.githubUrl = 'https://github.com/' + this.githubUsername
	} else {

[balupton]

Implemented with v7