fix: support Node v10.17+ and drop v8 (#76)

Author: teppeis

README.md

@@ -118,5 +118,5 @@ If `allowJs: true` in your `tsconfig.json`, assertions in `test/**/*.(js|jsx)` a
 [ci-url]: https://github.com/power-assert-js/espower-typescript/actions?query=workflow%3A%22Node.js+CI%22
 [deps-image]: https://david-dm.org/power-assert-js/espower-typescript.svg
 [deps-url]: https://david-dm.org/power-assert-js/espower-typescript
-[node-version]: https://img.shields.io/badge/Node.js%20support-v8,v10,v12-brightgreen.svg
+[node-version]: https://badgen.net/npm/node/espower-typescript
 [license]: https://img.shields.io/npm/l/espower-typescript.svg

package.json

@@ -4,7 +4,7 @@
   "version": "9.0.2",
   "author": "Teppei Sato <[email protected]>",
   "engines": {
-    "node": ">=8.10"
+    "node": ">=10.17"
   },
   "main": "index.js",
   "files": [