Add test to function posix_getlogin()

Increased the coverage lines 587-595 in file ext/posix/posix.c

User Groups: PHPVale   PHPSP   PHPDF    PHPWomenBR

Hangout presented by #PHPTestFestBrasil on 2017-11-14
https://www.youtube.com/watch?v=bBWkzZEadNo

Author: royopa

ext/posix/tests/posix_getlogin_basic.phpt

@@ -0,0 +1,31 @@
+--TEST--
+Test for function posix_getlogin() basic functionality
+--CREDITS--
+Rodrigo Prado de Jesus <royopa [at] gmail [dot] com>
+Lucas de Oliveira <contato@deoliveiralucas.net>
+Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
+Felipe Almeida <felipealmeida948@gmail.com>
+Ariana Kataoka <ariskataoka@gmail.com>
+Leonardo Gouveia <leogouv@gmail.com>
+User Groups: PHPVale
+             PHPSP
+             PHPDF
+             PHP Women
+Hangout presented by #phptestfestbrasil on 2017-11-14
+https://www.youtube.com/watch?v=bBWkzZEadNo
+--SKIPIF--
+<?php 
+    if(!extension_loaded("posix")) die("skip - POSIX extension not loaded");
+?>
+--FILE--
+<?php
+$username = posix_getpwuid(posix_geteuid())['name'];
+
+if (posix_getlogin() == false) {
+    $username = false;
+}
+
+var_dump($username == posix_getlogin());
+?>
+--EXPECT--
+bool(true)