Simplify the management of alpine version

[LaurentGoderre]

Salvages parts of #725

[chorrell]

Just needs a rebase to resolve the conflict.

[LaurentGoderre]

Ok, rebased!

[PeterDaveHello]

I suggest to clarify we're going to use single Alpine base image in the commit message.

[LaurentGoderre]

@PeterDaveHello that's already what we are doing so this is not changing.

[PeterDaveHello]

I know, just a suggestion that we can make the commit message more clear, not a request to change review ;)

[LaurentGoderre]

Done!

[PeterDaveHello]

Conflicts need to be solved.

[LaurentGoderre]

Done!

[chorrell]

there's something wrong with the updates script:

[christopher:~/github/docker-node] master ± ./update.sh 10
Updating version 10...
sed: 1: "10/alpine/Dockerfile": invalid command code /
Done!

Also, it's creating a bunch of new files:

[christopher:~/github/docker-node] master(+9/-9)* ± git status
On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git checkout -- <file>..." to discard changes in working directory)

	modified:   10/Dockerfile
	modified:   10/alpine/Dockerfile
	modified:   10/slim/Dockerfile
	modified:   10/stretch/Dockerfile

Untracked files:
  (use "git add <file>..." to include in what will be committed)

	10/Dockerfile-e
	10/alpine/Dockerfile-e
	10/slim/Dockerfile-e
	10/stretch/Dockerfile-e

no changes added to commit (use "git add" and/or "git commit -a")

[chorrell]

And it's messing up the alpine Dockerfile for v10;

[christopher:~/github/docker-node] master(+9/-9)* ± cat 10/alpine/Dockerfile | grep alpine
FROM alpine:0.0

[LaurentGoderre]

@chorrell you're running it on a Mac aren't you??

[chorrell]

Yes.

[LaurentGoderre]

I have gnu-sed on my mac but it's possible that the new sed commands don't work in POSIX