background_image Parameter not working

[AndreBerzun]

Thanks for this package, it's a real time saver 👍
Looking at the documentation though, I think this is a bug:

Describe the bug
Generating the splash screen seems to be only possible using the color attribute and not with a background_image.

To Reproduce
Using the following pubspec.yaml:

...
dev_dependencies:
  flutter_test:
    sdk: flutter
  mockito: ^4.1.3
  json_serializable: ^3.5.0
  build_runner: ^1.10.6
  flutter_launcher_icons: ^0.8.1
  flutter_native_splash: ^0.3.2

...

flutter_native_splash:
  background_image: assets/images/launch/launcher_background.png
  image: assets/images/launch/launcher_image.png
  android_gravity: fill_horizontal
  ios_content_mode: scaleAspectFit

I was not able to generate a splash screen.

The following message is printed to the terminal:

*** ERROR [flutter_native_splash] ***
InvalidConfigException
Your `flutter_native_splash` section does not contain a `color`.
pub finished with exit code 1

I thought I could use either a color or a background image?

Device (please complete the following information):

• OS: Android 9

Flutter doctor

[✓] Flutter (Channel stable, 1.22.4, on Linux, locale en_US.UTF-8)
    • Flutter version 1.22.4 at /home/andre/development/flutter
    • Framework revision 1aafb3a8b9 (4 months ago), 2020-11-13 09:59:28 -0800
    • Engine revision 2c956a31c0
    • Dart version 2.10.4

 
[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
    • Android SDK at /home/andre/Android/Sdk
    • Platform android-30, build-tools 29.0.2
    • Java binary at: /opt/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1248-b01)
    • All Android licenses accepted.

[!] Android Studio (version 3.3)
    • Android Studio at /opt/android-studio
    ✗ Flutter plugin not installed; this adds Flutter specific functionality.
    ✗ Dart plugin not installed; this adds Dart specific functionality.
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1248-b01)

[✓] Connected device (1 available)
    • TA 1012 (mobile) • NB1GAS3770900742 • android-arm64 • Android 9 (API 28)

! Doctor found issues in 1 category.

[AndreBerzun]

I'm gonna save you the trouble :) Just found this issue #22
Thanks!