Throw an error if you try to initiate a new SnowflakeUtil class instance (#1413)

src/util/Snowflake.js

@@ -8,6 +8,10 @@ let INCREMENT = 0;
  * A container for useful snowflake-related methods
  */
 class SnowflakeUtil {
+  constructor() {
+    throw new Error(`The ${this.constructor.name} class may not be instantiated.`);
+  }
+
   /**
    * A Twitter snowflake, except the epoch is 2015-01-01T00:00:00.000Z
    * ```