build: add circleci & gitlabci

This does some basic formal testing, just like done for packages.git.
Later compiling of device tree files, checking kmods or other more
specific tests could be done. However this is a first step to CI.

Signed-off-by: Paul Spooren <mail@aparcar.org>
1 job for ci in 14 seconds (queued for 3 minutes and 26 seconds)
Status Job ID Name Coverage
  Test
failed #345
doc

00:00:14

 
Name Stage Failure
failed
doc Test
Running on runner-8a1e19e7-project-203-concurrent-0 via builder1...
Reinitialized existing Git repository in /builds/openwrt/openwrt/.git/
Fetching changes...
Checking out 2b50ee8d as ci...

Skipping Git submodules setup
/bin/bash: line 82: $BASH_ENV: ambiguous redirect
$ cat >> $BASH_ENV <<EOF # collapsed multi-line command
ERROR: Job failed: exit code 1