Update tests to check for correct URLs

[tommy-mitchell]

Mocks open, package-json, and console.[error/log] as needed to test for correct outputs.

[tommy-mitchell]

Also just realized that this message is incorrect because we fallback to opening the NPM page if the resolved package.json doesn't contain a "repository" field:

npm-home/cli.js

Lines 45 to 51 in c0e7223

	const packageData = await packageJson(name, {fullMetadata: true});
	const {repository} = packageData;
	if (!repository) {
	await openNpmOrYarn(name);
	return;
	}

npm-home/cli.js

Line 68 in c0e7223

console.error(`${logSymbols.error} No \`repository\` or \`homepage\` field found in package.json. Please open an issue or pull request on ${name}`);

[sindresorhus]

It's unclear if you planned to fix #21 (comment) in this PR.