Use tilde versions for composer packages

Author: bcrowe

composer.json

@@ -20,9 +20,9 @@
         "cakephp/cakephp": "~3.0"
     },
     "require-dev": {
-        "phpunit/phpunit" : "4.*",
+        "phpunit/phpunit" : "~4.0",
         "scrutinizer/ocular": "~1.1",
-        "squizlabs/php_codesniffer": "2.3.*"
+        "squizlabs/php_codesniffer": "~2.3.0"
     },
     "autoload": {
         "psr-4": {