linting the code, and downgrade from es6 to es5

Author: huan

package.json

@@ -7,7 +7,7 @@
   "scripts": {
     "lint": "npm run lint:ts",
     "lint:ts": "tslint --project tsconfig.json --type-check",
-    "test": "npm run test:js && npm run test:ts",
+    "test": "npm run lint && npm run test:js && npm run test:ts",
     "test:js": "tap test.js",
     "test:ts": "ts-node test.ts",
     "test_ts": "ts-node node_modules/blue-tape/bin/blue-tape test_typescript.ts"

test.ts

@@ -7,9 +7,9 @@ const { test } = require('tap');
 test('TypeScript', async t => {
     t.plan(1);
 
-    let python = pythonBridge();
-    let a = 123, b = 321;
-    python.ex`
+    const python = pythonBridge();
+    const a = 123, b = 321;
+    await python.ex`
         def hello(a, b):
             return a + b
     `;

tsconfig.json

@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
-    "target": "es6"
+    "target": "es5"
+    , "lib": ["es2015"]
     , "module": "commonjs"
     , "outDir": "dist"
     , "declaration": true