[SR-10178] Make swift-docker a bit nicer

[stephencelis]

Previous ID	SR-10178
Radar	None
Original Reporter	@stephencelis
Type	Improvement

Additional Detail from JIRA

Votes	5
Component/s	Docker
Labels	Improvement
Assignee	@shahmishal
Priority	Medium

Watchers: @shahmishal

md5: 70d4cba53f116c5670beb07efed412eb

Issue Description:

It's nice that Swift has taken an official Docker recipe under its wing, but we end up not using it because:

1. It lags with releases (5.0 was not released alongside Xcode 10.2 and the official toolchain)

2. It doesn't provide access to toolchains as they're released, making it inconvenient to test newer toolchains on Docker images

Instead, we end up using @norio-nomura's excellent image: https://hub.docker.com/r/norionomura/swift

I'm sure he'd be interested in not maintaining it, though, should Apple catch up.

[weissi]

CC ianpartridge (JIRA User)

[shahmishal]

Pull request to add Swift 5.0 Dockerfiles was created around the same time Swift 5.0 released yesterday. (#134)

Once the PR has been reviewed, I will create another PR on https://github.com/docker-library/official-images to be added as official docker images. Updating the official docker page can take update 24hrs because it's not controlled by Swift community.

Official images are created and hosted by Docker.

[stephencelis]

@shahmishal Should I open a separate issue for the second point? It'd be nice to be able to use snapshots as they're released rather than have to wait for official version bumps.