Refresh dependencies and fix warnings

rollup.config.js

@@ -1,8 +1,7 @@
 import typescript from 'rollup-plugin-typescript2';
-import commonjs from 'rollup-plugin-commonjs';
-import nodeResolve from 'rollup-plugin-node-resolve';
-import babel from 'rollup-plugin-babel';
-import { terser } from 'rollup-plugin-terser';
+import commonjs from '@rollup/plugin-commonjs';
+import nodeResolve from '@rollup/plugin-node-resolve';
+import babel from '@rollup/plugin-babel';
 import serve from 'rollup-plugin-serve';
 import json from '@rollup/plugin-json';
 import styles from 'rollup-plugin-styles';
@@ -38,6 +37,7 @@ const plugins = [
   typescript(),
   json(),
   babel({
+    babelHelpers: 'bundled',
     exclude: 'node_modules/**',
   }),
   dev && serve(serveopts),