Different output at node and at browser

simple example
```javascript
const insane = require('insane');
console.log(insane('<a href="&#106;">test</a>'));
```
Running this under node gives `<a href="j">test</a>` see https://repl.it/repls/CloseMassiveArchitects
And running this under browser gives `<a href="&amp;#106;">test</a>` see https://codesandbox.io/s/k3ql74k5y5

This causes an issues with server side rendering.