No icon appearing on FloatingActionButton
Hello, I am currently trying to use Android-Iconics to add icons to, among other things, a `FloatingActionButton` from the official Google design support library. However (as the title suggests) I can't seem to get anything appear on the button. It works flawlessly on an ImageButton or an ImageView, but nothing shows for the `FloatingActionButton`... I am using the design library version 23.3.0, Android-Iconics version 2.5.11, and tried using Google Material Design Icons as well as the Material Design Iconic Font, but nothing seems to work. I am testing on Android 4.4.2.
It looks like the problem lies within the `VisibilityAwareImageButton` class, since it doesn't work with it either, but everything works fine with the `ImageButton` class, from which `VisibilityAwareImageButton` inherits... Or does the problem lie somewhere else ? I've only just started writing my application, so there is really nothing too complex or strange in it that might do something nasty, and this puzzles me...

``` xml
<ImageButton
        android:layout_width="48dp"
        android:layout_height="48dp"
        app:ico_color="@android:color/darker_gray"
        app:ico_icon="gmi-account-add"
        app:ico_size="24dp" /> <!-- This works perfectly -->

<android.support.design.widget.FloatingActionButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        android:layout_marginBottom="@dimen/activity_vertical_margin"
        android:layout_marginEnd="@dimen/activity_horizontal_margin"
        android:layout_marginRight="@dimen/activity_horizontal_margin"
        android:clickable="true"
        app:fabSize="normal"
        app:ico_color="@android:color/darker_gray"
        app:ico_icon="gmi-account-add"
        app:ico_size="24dp" /> <!-- This doesn't -->
```
