Updated composer

Author: paquettg

composer.json

@@ -15,17 +15,18 @@
     ],
     "require": {
         "php": ">=5.4",
-        "paquettg/string-encode": "0.1.0"
+        "paquettg/string-encode": "~0.1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "4.8.*",
-        "satooshi/php-coveralls": "0.6.*",
-        "mockery/mockery": "0.9.*"
+        "phpunit/phpunit": "~4.8.0",
+        "satooshi/php-coveralls": "~0.6.0",
+        "mockery/mockery": "~0.9.0"
     },
     "autoload": {
         "psr-0": { 
         	"PHPHtmlParser": "src/"
        	}
     },
-    "minimum-stability": "dev"
+    "minimum-stability": "dev",
+    "prefer-stable": true
 }