Remove unused dep + file

lib/utils/singleton.js

@@ -1,35 +0,0 @@
-const Symbol = require('es6-symbol');
-
-class Singleton {
-  constructor() {
-    const Class = this.constructor;
-    if (!Class[this.singleton]) {
-      Class[this.singleton] = this;
-    }
-
-    return Class[this.singleton];
-  }
-
-  static get instance() {
-    if (!this[this.singleton]) {
-      this[this.singleton] = new this();
-    }
-
-    return this[this.singleton];
-  }
-
-  static set instance(instance) {
-    this[this.singleton] = instance;
-    return this[this.singleton];
-  }
-
-  static get singleton() {
-    return Symbol(this.namespace);
-  }
-
-  static reset() {
-    delete this[this.singleton];
-  }
-}
-
-export default Singleton;

package.json

@@ -81,7 +81,6 @@
     "wml": "0.0.82"
   },
   "dependencies": {
-    "bows": "^1.6.0",
-    "es6-symbol": "^3.1.0"
+    "bows": "^1.6.0"
   }
 }