fix(node6): support node 6 (#19)

package.json

@@ -34,10 +34,12 @@
   "dependencies": {
     "@types/argparse": "^1.0.33",
     "@types/aws-sdk": "^2.7.0",
+    "@types/bluebird": "^3.5.20",
     "@types/js-yaml": "^3.11.1",
     "@types/node": "^9.6.4",
     "argparse": "^1.0.10",
     "aws-sdk": "^2.224.1",
+    "bluebird": "^3.5.1",
     "js-yaml": "^3.11.0",
     "nodecredstash": "^2.0.2"
   },

src/resolvers.ts

@@ -1,9 +1,11 @@
 import * as AWS from 'aws-sdk';
 import { CloudFormation } from 'aws-sdk';
 import { DescribeStacksOutput } from 'aws-sdk/clients/cloudformation';
-import { promisify } from 'util';
+
 const Credstash = require('nodecredstash');
 
+import { promisify } from 'bluebird';
+
 import { ResolverMap, Config } from './types';
 
 
@@ -47,7 +49,7 @@ export const resolvers: ResolverMap = {
   },
   cred: async (argument: string, config: Config) => {
     const credstash = new Credstash({ awsOpts: { region: config.awsRegion } });
-    const promisified = promisify(credstash.getSecret);
+    const promisified = promisify<string, object>(credstash.getSecret, { context: credstash });
     return promisified({ name: argument })
       .catch((error: Error): string => {
         console.warn(`Could not load value ${argument} from credstash: ${error}`);

yarn.lock

@@ -107,6 +107,10 @@
   dependencies:
     aws-sdk "*"
 
+"@types/bluebird@^3.5.20":
+  version "3.5.20"
+  resolved "https://registry.yarnpkg.com/@types/bluebird/-/bluebird-3.5.20.tgz#f6363172add6f4eabb8cada53ca9af2781e8d6a1"
+
 "@types/js-yaml@^3.11.1":
   version "3.11.1"
   resolved "https://registry.yarnpkg.com/@types/js-yaml/-/js-yaml-3.11.1.tgz#ac5bab26be5f9c6f74b6b23420f2cfa5a7a6ba40"