Snapcraft 2.23 has been released

[Sergio Schvezov]

Hello snapcrafters!

We are pleased to announce the release of version `2.23` of snapcraft 
has been released:
https://launchpad.net/snapcraft/+milestone/2.23

Here's the list of features that you can find in this new release:

- General cache mechanism for future features that require it.
- Plumbing layer in place for pushing deltas instead of full sized snaps.
- Source management for parts is now in the core making it much more 
robust (and core).
- FTP is now a valid source.
- New command `snapcraft enable-ci` to make it easy for developers to 
enable continuous delivery when using travis for continuous integration 
to push to a store development channel.


Many minor fixes are available as well:

- The `nodejs` plugin now correctly manages `run` statements.
- The `cmake` plugin now includes the capabilities of the `make` plugin.
- The parts parser now supports remote dependencies correctly.
- `build-packages` are now `apt` marked as automatically installed.
- bash completion improvements when auto-completing commands that take 
snap files.
- Proper change tracking for all core properties of a part.
- Improved terminal support when `TERM=dumb` is set or not on a tty.
- Store error improvements for registering and login.


Some testing improvements have been made too:

- Migrated to `testtools` for more comprehensive test suites.
- Replaced `subTests` with `testscenarios`.
- Added tooling to build external snaps as part of our release process


This release has seen some contributions from outside of the snapcraft 
core team, so we want to give a shout out to these folks, here's a team 
thank you for:

- Celso Providelo
- Kelvin Li
- Kit Randel
- Marco Trevisan
- Parameswaran Sivatharman

To get the source for this release check it out at
https://github.com/ubuntu-core/snapcraft/releases/tag/2.23

A great place to collaborate and discuss features, bugs and ideas on
snapcraft is snapcraft at lists.snapcraft.io mailing list or on the snapcraft
channel on Rocket Chat https://rocket.ubuntu.com/channel/snapcraft

To file bugs, please go to https://bugs.launchpad.net/snapcraft/+filebug.

Happy snapcrafting!
-- Sergio and the team

PS: The online copy of the release notes can be found on 
https://github.com/snapcore/snapcraft/releases/tag/2.23