Random user support

[mabrarov]

• Consistent line ending for scripts across different Git configurations and OS.
• Support of running container with user different than the one which is specified in the image.
• Minor optimization of layers.

Testing:

container_id="$(docker run -d -u 100500 mendhak/http-https-echo)" \
&& sleep 5s \
&& docker container inspect "${container_id}" -f '{{ .State.Status }}' \
&& docker rm -fv "${container_id}" >/dev/null

Expected output (correct output when the image is built from the source branch of this PR):

running

Output when using original image built from master branch:

exited

[mendhak]

Ah so sorry I was delayed! OK all good now. Thanks for fixing the permissions also you added a test yay!

It's merged. It's in tag :19.