add scrypt to workers.

lib/bcoin/workers.js

@@ -232,6 +232,22 @@ Workers.prototype.mine = function mine(attempt, callback) {
   return this.execute('mine', [data], -1, callback);
 };
 
+/**
+ * Execute scrypt job (no timeout).
+ * @param {Buffer} passwd
+ * @param {Buffer} salt
+ * @param {Number} N
+ * @param {Number} r
+ * @param {Number} p
+ * @param {Number} len
+ * @param {Function} callback
+ * @returns {Buffer}
+ */
+
+Workers.prototype.scrypt = function scrypt(passwd, salt, N, r, p, len, callback) {
+  return this.execute('scrypt', [passwd, salt, N, r, p, len], -1, callback);
+};
+
 /**
  * Represents a worker.
  * @exports Worker
@@ -685,6 +701,23 @@ jobs.mine = function mine(data) {
   return attempt.mineSync();
 };
 
+/**
+ * Execute scrypt() on worker.
+ * @see scrypt
+ * @param {Buffer} passwd
+ * @param {Buffer} salt
+ * @param {Number} N
+ * @param {Number} r
+ * @param {Number} p
+ * @param {Number} len
+ * @returns {Buffer}
+ */
+
+jobs.scrypt = function scrypt(passwd, salt, N, r, p, len) {
+  var scrypt = require('./scrypt');
+  return scrypt(passwd, salt, N, r, p, len);
+};
+
 /**
  * Framer
  * @constructor