Update CHANGELOG for 1.4.0
Update CHANGELOG for 1.4.0

soiff/gitlab-ci-multi-runner,ayufan/gitlab-ci-multi-runner,soiff/gitlab-ci-multi-runner,soiff/gitlab-ci-multi-runner,ayufan/gitlab-ci-multi-runner,ayufan/gitlab-ci-multi-runner,hu19891110/gitlab-ci-multi-runner,hu19891110/gitlab-ci-multi-runner,hu19891110/gitlab-ci-multi-runner