Multiline column name does not work with strings

I'm trying to add a column name that has a multiline string, i.e: `${line1}\n${line2}`
But the result is: "line1line2"

## Expected Behavior
What I wanted to see is:
```
line1
line2
```

## Current Behavior
What I see:
```
line1line2
```

## Workaround
The problem does not happen if a use an HTML object instead of a template string such as:
```

```
But then when I download the table data I get [object Object] for the referred column
## Your Environment

| Tech | Version |
|--------------|---------|
| @material-ui/core | 3.8.3 |
| MUI-datatables | 2.0.0-beta-32 |
| React | 16.5.2 |
| browser | chrome |