Merge branch 'example/cahn_hilliard' into 'develop'

Example/cahn hilliard

See merge request !102
4 jobs for develop in 26 minutes and 49 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Test
passed #8815
debian:10 clang-6-libcpp-17

00:26:49

passed #8814
debian:10 gcc-8-17

00:18:11

passed #8816
debian:9 gcc-6-14

00:19:25

passed #8817
ubuntu:18.04 clang-6-17

00:24:55