Add Util\AuthHelper unit test coverage (#8863)
Add Util\AuthHelper unit test coverage (#8863)

* 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.
stof/composer,fabpot/composer,johnstevenson/composer,staabm/composer,pierredup/composer,floverdevel/composer,naderman/composer,composer/composer,localheinz/composer,stefangr/composer,milleruk/composer,alcohol/composer,nicolas-grekas/composer