* Add AuthHelper::addAuthenticationHeader() test on missing authentication credentials.
* Add AuthHelper::addAuthenticationHeader() test on bearer password.
* Add AuthHelper::addAuthenticationHeader() test on Github token.
* Add AuthHelper::addAuthenticationHeader() test on Gitlab Oauth token.
* Add $authenticationDisplayMessage write expectation to AuthHelper::addAuthenticationHeader() tests.
* Add AuthHelper::addAuthenticationHeader() test on Gitlab private token.
* Add AuthHelper::addAuthenticationHeader() test on Bitbucket Oauth token.
* Add AuthHelper::addAuthenticationHeader() test on Bitbucket public urls.
* Add AuthHelper::addAuthenticationHeader() test on Basic Http Authentication.
* Add AuthHelper::isPublicBitBucketDownload() tests.
* Rename AuthHelperTest $credentials variable to $auth.
* Add AuthHelper::storeAuth() test for auto-store option.
* Add AuthHelper::storeAuth() test for user prompt and y(es) answer.
* Add AuthHelper::storeAuth() test for user prompt and n(o) answer.
* Add AuthHelper::storeAuth() test for user prompt with invalid answer.
* Add AuthHelper::promptAuthIfNeeded() test for Github authentication failure.
- add GitHub hard dependency mock (new GitHub(...) mock)
* Run AuthHelper::promptAuthIfNeeded() tests only with PHP > 5.3
* Run AuthHelper::promptAuthIfNeeded() tests only with PHP >= 5.4
* Run AuthHelper::promptAuthIfNeeded() tests only with PHP 5.4
* Exclude PHPStan analyses of '../tests/Composer/Test/Util/Mocks/*'
* Exclude AuthHelper::promptAuthIfNeeded() tests from current pull request.
* Extract repetitive AuthHelperTest authentication expectation into a method.
Michael Chekin