Updated to most recent releases of all dependencies

Set minimum supported versions to most recent releases of dependencies.
In cases where 2.X and 3.X versions exist, and they are compatible, the
most recent versons of each are `||`'d.

composer.json

@@ -14,14 +14,14 @@
     },
     "require": {
         "php": "^5.6 || ^7.0",
-        "zendframework/zend-stdlib": "^2.7 || ^3.0",
+        "zendframework/zend-stdlib": "^2.7.7 || ^3.1",
         "psr/container": "^1.0"
     },
     "require-dev": {
-        "zendframework/zend-filter": "^2.6",
-        "zendframework/zend-i18n": "^2.6",
-        "zendframework/zend-json": "^2.6.1",
-        "zendframework/zend-servicemanager": "^2.7.5 || ^3.0.3",
+        "zendframework/zend-filter": "^2.7.1",
+        "zendframework/zend-i18n": "^2.7.3",
+        "zendframework/zend-json": "^2.6.1 || ^3.0",
+        "zendframework/zend-servicemanager": "^2.7.8 || ^3.2.1",
         "phpunit/phpunit": "^5.7 || ^6.0",
         "zendframework/zend-coding-standard": "~1.0.0"
     },