bump version to 0.4.0, update changelogs, README

4 jobs for v0.4.0 in 1 minute and 8 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Build
passed #354207
build:debian:stretch

00:00:39

passed #354206
build:el7

00:00:44

passed #354205
build:tarball

00:00:21

 
  Test
passed #354208
test:el7

00:00:24