#264 widgets do no support null or undefined children
#264 widgets do no support null or undefined children

1. CardItem support for null or undefined children,
2. Airbnb rules.

GeekyAnts/NativeBase,GeekyAnts/NativeBase,chaitanya0bhagvan/NativeBase,GeekyAnts/NativeBase,GeekyAnts/NativeBase,GeekyAnts/NativeBase,sampsasaarela/NativeBase