Readme Fab sample

[apex39]

Sample class of Fab shown in README should contain all three defaulf constructors:

public Fab(Context context) {
        super(context);
    }

public Fab(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

public Fab(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

IDE yells that class has no default constructor but a programmer who has no idea how widgets are implemented can run into XML inflating error when implementing only one constructor.

[Gordon]

Putting this in the readme is unnecessary since it's obvious the constructors are needed and the IDE helps autocomplete them.