Bump version to 0.4.0
Bump version to 0.4.0

Co-authored-by: Andrew Bates <7a27e4ba2cef1118180a85ac250e01557f93fc37@mavenlink.com>
Co-authored-by: Alan Wong <91e38e63b890fbb214c8914809fde03c73e7f24d@mavenlink.com>

mavenlink/arboreal