Make canvas transparent

[Slowyn]

Problem:

Current implementation doesn't allow to create qr-code with transparent backgrounds.

This PR turns transparency by default.

[yhsiang]

@cssivision will you merge this?

This PR fixed our problem, when we have two themes, light and dark.

QRCode view will break in dark view, so we need make background color be transparent.

Especially we have this problem on android phone.

[balthazar]

Published react-native-qrcode-transparent based on this PR while we wait

[Slowyn]

Guys, sad news, the repo is officially no longer maintained. Someone should take a project at his hand.
@balthazar It would be nice if you could maintain and develop your fork further.
You should make PR with the link from this project to yours.
@cssivision Are you agree to this and will you accept the incoming PR?

[balthazar]

Unfortunately not possible for me, as I already have a couple repos to maintain.

[Slowyn]

Well, probably I can take maintenance. We'll see.

[cssivision]

that is great, if someone can take the maintenance.

[AkshatGiri]

I can commandeer the repo if the the owner is okay with it.