[cleanup][fluid][brineair] Remove assert in constexpr mapping function

Closes #879

See merge request !2081

[seqsolverbackend] Fix Dune::Hybrid::size deprecation warning

See merge request !2083

[changelog] Add template for 3.3

See merge request !2080

[readme] Fix build badge link

See merge request !2079

Fix tests that fail with minimal setup

Closes #871

See merge request !2051

[1pni][3pni][test] use ILU0 with BiCGSTAB for 1pni and 3pni tests to ensure convergence with minimal setup (no UMFPack)

The conduction tests without UMFPack used SSOR as coarse grid solver 
which did not converge as well and lead to different timestep sizes.

Needed to ensure convergence with minimal setup (no UMFPack) for
test_2p_incompressible_tpfa_oilwet. The coarse grid solver is changed to
SSOR when UMFPack is not available, which did not converge as well.

[changelog] add section on GridView property deprecation

See merge request !2076

Due to !1905

[readme] Update build badges

See merge request !2075

[examples][changelog] added new examples and ex. doc to changelog

See merge request !2073

[common][pdesolver] Fix Dune::Hybrid::size deprecation warning

Closes #872

See merge request !2066

[io][vtkfunction] Mark function arguments as maybe_unused to avoid compiler warning

See merge request !2067

Update CHANGELOG.md

See merge request !2068

* use forward declare to avoid include of MultiTypeBlockMatrix

[opm][cmake] adapt to changes in OPM

Closes #875

See merge request !2061

[test][2p][fracture] fix failing 2p fracture tests

Closes #863

See merge request !2042

* Reduced inital dt
* Fixed timesteps
* Adapted the reference solution

[examples][biomin] remove constexpr where necessary

See merge request !2063

[examples][biomin] Add biomineralization example

See merge request !2038

Johannes Hommel authored Jul 31, 2019 and Dennis Gläser committed Apr 27, 2020

with contributions by Felix Weinhardt
and some proof reading by Timo Koch and Dennis Gläser