move to more recent lib and target with typescript

Author: kristoferbaxter

package.json

@@ -42,6 +42,7 @@
   "devDependencies": {
     "@types/acorn": "4.0.5",
     "@types/estree": "0.0.39",
+    "@types/node": "12.11.5",
     "@types/temp-write": "3.3.0",
     "ava": "2.4.0",
     "builtins": "2.0.1",

tsconfig.json

@@ -2,12 +2,12 @@
   "compileOnSave": true,
   "compilerOptions": {
     "lib": [
-      "es2017",
+      "esnext",
     ],
     "outDir": "transpile",
     "sourceMap": true,
     "moduleResolution": "node",
-    "target": "es2017",
+    "target": "esnext",
     "baseUrl": ".",
     "allowJs": false,
     "noUnusedLocals": true,