test: bson corpus spec runner calling wrong fn (#436)

* test: bson corpus spec runner calling wrong fn

* lint: fix decimal 128 import error

Author: durran

test/node/bson_corpus_tests.js

@@ -2,7 +2,6 @@
 
 const Buffer = require('buffer').Buffer;
 const BSON = require('../register-bson');
-const Decimal128 = BSON.Decimal128;
 const EJSON = BSON.EJSON;
 
 const deserializeOptions = {
@@ -192,7 +191,7 @@ describe('BSON Corpus', function () {
         describe('parseErrors', function () {
           scenario.parseErrors.forEach(p => {
             it(p.description, function () {
-              expect(() => Decimal128.fromString(scenario.string)).to.throw();
+              expect(() => jsonToNative(scenario.string)).to.throw();
             });
           });
         });