Update tsconfig.json

Author: dan-silver

tsconfig.json

@@ -6,7 +6,7 @@
     "moduleResolution": "node",
     "removeComments": true,
     "sourceMap": true,
-    "target": "es6",
+    "target": "es5",
     "declaration": true,
     "outDir": "lib/"
   },
@@ -19,4 +19,4 @@
       "./src/index.ts",
       "./test/*.ts"
   ]
-}
+}