Custom Font Icon not recognized in xml
When i want to use an Icon of my Customfont in the xml like:

```
<com.mikepenz.iconics.view.IconicsImageView
        android:id="@+id/ivCodeCount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        app:iiv_icon="fbd_barcode"
        app:iiv_padding="2dp"
        app:iiv_size="20dp" />
```

it's not shown. However when i use `ivCodeCount.icon!!.icon(FBDFontModule.Icon.fbd_barcode)` it's working.

I initialize it in the App file like (it's a java file): 
```
Iconics.init(getApplicationContext());
Iconics.registerFont(FBLFontModule.INSTANCE);
```

I also tried fbd_barcode `fbd-barcode` and `{fbd-barcode}` and `{fbd_barcode}`.
In the error logs i can find: 
`E/Iconics: Wrong icon name: fbd-barcode` or E/Iconics: `Wrong icon name: fbd-barcode` but when i use `{fbd-barcode}`  i see nothing in the error logs (but also no icon).

I use:
- library version 4.0.2
- support library version 1.0.0
- Used gradle build tools version 3.5.3
- Used tooling / Android Studio version 3.5.3