hashPassword fall-through if there's no password (#287)

* hashPassword fall-through if there's no password

The user should have already run a `requireAuth` hook by this point.

* JSHint

packages/authentication/src/hooks/hash-password.js

@@ -1,7 +1,5 @@
-import errors from 'feathers-errors';
 import bcrypt from 'bcryptjs';
 
-
 const defaults = { passwordField: 'password' };
 
 export default function (options = {}) {
@@ -34,11 +32,7 @@ export default function (options = {}) {
     }
 
     if (password === undefined) {
-      if (!hook.params.provider) {
-        return hook;
-      }
-
-      throw new errors.BadRequest(`'${options.passwordField}' field is missing.`);
+      return hook;
     }
 
     return new Promise(function (resolve, reject) {