fixing composer package versions, thanks @jelhan (#84)

composer.json

@@ -18,9 +18,9 @@
         }
     ],
     "require": {
-        "php": "^5.2.6 || ^7.0",
-        "paragonie/random_compat": "^2.0",
-        "yzalis/identicon": "^1.1"
+        "php": "^5.3.0 || ^7.0",
+        "paragonie/random_compat": "2.0.4",
+        "yzalis/identicon": "1.1.0"
     },
     "require-dev": {
         "codacy/coverage": "dev-master",