Set bin directory for composer.

Author: BernardoSilva

composer.json

@@ -15,6 +15,9 @@
             "FontLib\\": "src/FontLib"
         }
     },
+    "config": {
+      "bin-dir": "bin"
+    },
     "require-dev": {
         "phpunit/phpunit": "^4.8"
     }