Updates PHPUnit and PHP dependencies

- Removes support for PHP 5.5 and HHVM
- Updates PHPUnit to the 5.7 and 6.0 series

.gitignore

@@ -11,7 +11,6 @@ doc/html/
 zf-mkdoc-theme/
 
 clover.xml
-composer.lock
 coveralls-upload.json
 phpunit.xml
 vendor

composer.json

@@ -14,17 +14,17 @@
     },
     "require": {
         "php": "^5.6 || ^7.0",
-        "zendframework/zend-config": "^2.6 || ^3.1",
-        "zendframework/zend-eventmanager": "^2.6.2 || ^3.0",
-        "zendframework/zend-stdlib": "^2.7 || ^3.0"
+        "zendframework/zend-config": "^3.1 || ^2.6",
+        "zendframework/zend-eventmanager": "^3.2 || ^2.6.3",
+        "zendframework/zend-stdlib": "^3.0 || ^2.7"
     },
     "require-dev": {
         "zendframework/zend-console": "^2.6",
         "zendframework/zend-di": "^2.6",
         "zendframework/zend-loader": "^2.5",
         "zendframework/zend-mvc": "^2.7",
-        "zendframework/zend-servicemanager": "^2.7.5 || ^3.0.3",
-        "phpunit/PHPUnit": "~4.0",
+        "zendframework/zend-servicemanager": "^3.0.3 || ^2.7.5",
+        "phpunit/phpunit": "^6.0.8 || ^5.7.15",
         "zendframework/zend-coding-standard": "~1.0.0"
     },
     "suggest": {
@@ -33,15 +33,16 @@
         "zendframework/zend-mvc": "Zend\\Mvc component",
         "zendframework/zend-servicemanager": "Zend\\ServiceManager component"
     },
-    "minimum-stability": "dev",
-    "prefer-stable": true,
     "extra": {
         "branch-alias": {
             "dev-master": "2.7-dev",
             "dev-develop": "2.8-dev"
         }
     },
     "autoload-dev": {
+        "files": [
+            "test/autoload.php"
+        ],
         "psr-4": {
             "ListenerTestModule\\": "test/TestAsset/ListenerTestModule/",
             "ZendTest\\ModuleManager\\": "test/"