Add extended metadata support for DayOne Classic (#928)

* Updating changelog [ci skip]

* Incrementing version to v2.4 [ci skip]

* [DayOne] remove extra spaces from the titles of edited DayOne entries

Otherwise, a leading space was being introduced

* [DayOne] maintain existing tags stored in DayOne metadata

* [DayOne] brings back extended DayOne attributes

* [DayOne] maintain metadata on edited entries

Fixes #358, See also #159

* [DayOne Exporter] apply black formatting

* [JSON Exporter] add support for extended DayOne Metadata

* [DayOne] [Tests] test that extended DayOne metadata is added to new entries

Co-authored-by: Jrnl Bot <jrnl.bot@gmail.com>

CHANGELOG.md

@@ -1,5 +1,24 @@
 # Changelog
 
+## [v2.4](https://pypi.org/project/jrnl/v2.4/) (2020-04-25)
+
+[Full Changelog](https://github.com/jrnl-org/jrnl/compare/v2.4-beta...v2.4)
+
+**Implemented enhancements:**
+
+- Upgrade license to GPLv3 [\#918](https://github.com/jrnl-org/jrnl/pull/918) ([wren](https://github.com/wren))
+
+**Build:**
+
+- Update makefile to match pipeline better [\#919](https://github.com/jrnl-org/jrnl/pull/919) ([wren](https://github.com/wren))
+
+**Updated documentation:**
+
+- Clean up readme file [\#924](https://github.com/jrnl-org/jrnl/pull/924) ([wren](https://github.com/wren))
+- Clarify that editing config isn't always destructive [\#923](https://github.com/jrnl-org/jrnl/pull/923) ([Epskampie](https://github.com/Epskampie))
+
+# Changelog
+
 ## [Unreleased](https://github.com/jrnl-org/jrnl/)
 
 [Full Changelog](https://github.com/jrnl-org/jrnl/compare/v2.4.2...HEAD)