Merge branch 'release_candidate' into 'master'

Release version 0.4.0

Closes #33 and #15

See merge request chronusq/chronusq_dev!89
4 jobs for v0.4.0 in 114 minutes and 12 seconds (queued for 45 minutes and 47 seconds)
latest
Status Job ID Name Coverage
  Build
passed #4511
build_gcc

00:47:18

passed #4510
build_intel

00:44:08

passed #4522
build_mpi_gcc

01:04:03

failed #4512
build_mpi_gcc

01:01:58