Ref https://github.com/svg/svgo/issues/1596
At the moment dynamic import may randomly fail with segfault.
To workaround this for some users .cjs extension is loaded
exclusively with require.
Ref https://github.com/svg/svgo/issues/1579
In config of course. Projects with type:module can now use modules to
export config
```js
export default {
plugins: []
}
```
Also added support for resolving svgo.config.mjs and svgo.config.cjs.
Moved loadConfig tests to svgo-node tests.
mjs test is skipped for now in node 10, just don't use modules there
`os` package in js2svg module bothered me for a long time.
We had to hack rollup to mock it for browser.
Thanks to https://github.com/svg/svgo/pull/1546 we now can pass eol from
svgo-node entry point and simplify build.
Ref https://github.com/svg/svgo/issues/1327
Config file now can only be js. `svgo.config.js` is searched by default.
Otherwise any js module specified in `--config` cli flag.
Config loader is exposed in entry point as `loadConfig(configFile, cwd)`.
