add ca-certificates to allow wget and clone, restructure

3 jobs for feature/first-install-ci-draft in 70 minutes and 20 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Test
passed test-basic #49750

00:30:03

failed test-external #49871

00:40:16

failed test-external #49751

00:15:04

 
Name Stage Failure
failed
test-external Test
/usr/bin/ld: poisson-pq2.cc:(.text.startup+0x1d79): undefined reference to `Dune::UGGrid<2>::maxLevel() const'
/usr/bin/ld: poisson-pq2.cc:(.text.startup+0x1db7): undefined reference to `Dune::UGGridEntity<0, 2, Dune::UGGrid<2> const>::setToTarget(UG::D2::element*, Dune::UGGrid<2> const*)'
collect2: error: ld returned 1 exit status
make[2]: *** [examples/CMakeFiles/poisson-pq2.dir/build.make:110: examples/poisson-pq2] Error 1
make[1]: *** [CMakeFiles/Makefile2:1982: examples/CMakeFiles/poisson-pq2.dir/all] Error 2
make: *** [Makefile:163: all] Error 2
--- Failed to build dune-functions ---
Terminating dunecontrol due to previous errors!
Cleaning up file based variables
ERROR: Job failed: exit code 1