Automatically trigger GitLab Pages pipelines

Whenever master or one for the v9_* branches gets updated, the current
ARM should be published on GitLab Pages.  Add a pipeline stage which
takes care of triggering GitLab Pages pipelines.  Extend the lifetime of
artifact archives containing the ARM to prevent GitLab Pages pipelines
from failing due to artifacts being unavailable.
27 jobs for 565-automatically-trigger-gitlab-pages-pipelines in 9 minutes and 53 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Precheck
passed #70393
amd64 docker linux
precheck:debian:sid:amd64

00:00:21

 
  Build
passed #70394
amd64 docker linux
build:centos:centos6:amd64

00:02:45

passed #70395
amd64 docker linux
build:centos:centos7:amd64

00:02:33

passed #70396
amd64 docker linux
build:clang:debian:stretch:amd64

00:02:02

passed #70400
i386 docker linux
build:clang:debian:stretch:i386

00:02:07

passed #70397
amd64 docker linux
build:debian:jessie:amd64

00:01:37

passed #70399
amd64 docker linux
build:debian:sid:amd64

00:02:28

passed #70401
i386 docker linux
build:debian:sid:i386

00:01:46

passed #70398
amd64 docker linux
build:debian:stretch:amd64

00:01:45

passed #70402
amd64 docker linux
pkcs11:build:debian:sid:amd64

00:02:46

 
  Test
passed #70403
amd64 docker linux
docs:debian:sid:amd64

00:01:00

passed #70417
amd64 docker linux
install:debian:sid:amd64

00:01:55

passed #70419
amd64 docker linux
pkcs11:systemtest:debian:sid:amd64

00:05:12

passed #70418
amd64 docker linux
pkcs11:unittest:debian:sid:amd64

00:00:51

passed #70411
amd64 docker linux
systemtest:centos:centos6:amd64

00:04:57

passed #70412
amd64 docker linux
systemtest:centos:centos7:amd64

00:06:21

passed #70413
amd64 docker linux
systemtest:debian:jessie:amd64

00:05:04

passed #70415
amd64 docker linux
systemtest:debian:sid:amd64

00:04:49

passed #70416
i386 docker linux
systemtest:debian:sid:i386

00:06:43

passed #70414
amd64 docker linux
systemtest:debian:stretch:amd64

00:06:31

passed #70404
amd64 docker linux
unittest:centos:centos6:amd64

00:01:02

passed #70405
amd64 docker linux
unittest:centos:centos7:amd64

00:00:52

passed #70409
amd64 docker linux
unittest:clang:debian:stretch:amd64

00:00:42

passed #70406
amd64 docker linux
unittest:debian:jessie:amd64

00:01:03

passed #70408
amd64 docker linux
unittest:debian:sid:amd64

00:00:56

passed #70410
i386 docker linux
unittest:debian:sid:i386

00:00:45

passed #70407
amd64 docker linux
unittest:debian:stretch:amd64

00:00:44