Resolve "Unify guards for uggrid"

Closes #1043

See merge request !2676

[test][math] Lower precision for polynomial test

See merge request !2671

Timo Koch authored Jun 02, 2021 and Dennis Gläser committed Jun 02, 2021

When the roots are very close together the inversion becomes ill-conditioned.
Exclude these cases from the random generation, test some corner cases
with close roots and decrease the tolerance for root comparison.

[doc] Add comment in release issue template

See merge request !2672

[ci] test release branches

See merge request !2669

[readme] Update to GitlabCI

See merge request !2668

[ci] find ref commit in check-pipeline

See merge request !2663

Dennis Gläser authored Jun 02, 2021 and Timo Koch committed Jun 02, 2021

This allows us to psas that reference commit downstream to e.g.
dumux-lecture

[handbook] Fix path of example and add hint to website guide

See merge request !2666

[handbook] Fix and update installation instructions

See merge request !2664

In particular remove non-recommended installation command that also
contained an outdated --use-cmake option which doesn't exist anymore.

[test][pnm] Fix test label

See merge request !2662

[test] Increase timeout of tests that take long without compiler optimisations

See merge request !2661

For the test coverage report the test suite has to be run in debug mode to get useful line annotations.

[test] Increase timeout of tests that take long without compiler optimisations

See merge request !2660

For the test coverage report the test suite has to be run in debug mode to
get useful line annotations.

[ci] make pipeline search more robust

See merge request !2659

the CI enters the repo in a detached HEAD state, and thus, the query if
a pipeline was run on the same branch failed. We now check the last
commits.

[ci] fix target tree argument

See merge request !2657

[ci] Use api read token for read access

See merge request !2655

Feature/continuous master pipeline status

See merge request !2644

The commands (e.g. pipeline queries via API) may contain sensible
information that we don't want to display e.g. in the output of jobs
from the GitLab CI