DevKit updates (#4308)

.travis/install_test.sh

@@ -5,9 +5,9 @@ mkdir --parents "${HOME}/bin"
 
 # PHPUnit install
 if [ ${TRAVIS_PHP_VERSION} '<' '5.6' ]; then
-    PHPUNIT_PHAR=phpunit-old.phar
+    PHPUNIT_PHAR=phpunit-4.8.phar
 else
-    PHPUNIT_PHAR=phpunit.phar
+    PHPUNIT_PHAR=phpunit-5.7.phar
 fi
 wget "https://phar.phpunit.de/${PHPUNIT_PHAR}" --output-document="${HOME}/bin/phpunit"
 chmod u+x "${HOME}/bin/phpunit"