Execute a file

I have a `.sh` file to be executed. Is there a way to do that with shelljs?
Below does not work on Windows:

```
var scriptToRun = path.resolve('./', 'shells/', 'myScript.sh');
shell.exec(scriptToRun, { async: true })
```

**myScript.sh**

```
#!/bin/sh

VAR1="asd"
echo $VAR1
```
