Merge tag '0.4.0' into develop

Release 0.4.0

 - Now using /meta.edn not .edn
 - Msc. bugfixes
Dirs not files from the 0.4.0 /meta.edn change
Transition to alt. version library
Just use /notes.md for simplicity
Start working on adding tests of the fs
Tighten up list-groups-test a bit
Reorder
Add list-ns-test
Add list-def-test
Add write-meta-test
Add list-prior-versions-test
Add more test files
Don't default to 1.0.0
Whitespace
Assert the right key
Naming, read-write-notes-test
Patch so that (comp demunge munge) is ident
Use generative testing of (· demunge munge)
Fix more issues with munge
Bumped version to 0.5.0