Update changelog and upgrade guide for 5.0.0 (#59)

Author: Lars-Magnus Skog

CHANGELOG.md

@@ -2,6 +2,20 @@
 
 ## [Unreleased]
 
+## [5.0.0] - 2018-12-21
+
+### Changed
+* Upgrade `abstract-leveldown` dependency from `~5.0.0` to `~6.0.0` (@ralphtheninja)
+* Upgrade `standard` devDependency from `^11.0.0` to `^12.0.0` (@ralphtheninja)
+* Tweak copyright years for less maintenance (@ralphtheninja)
+
+### Added
+* Add `nyc` and `coveralls` (@ralphtheninja)
+
+### Removed
+* Remove contributors from `package.json` (@ralphtheninja)
+* Remove node 9 (@ralphtheninja)
+
 ## [4.0.2] - 2018-05-30
 
 ### Changed
@@ -174,7 +188,8 @@ No changes.
 
 :seedling: First release. (@rvagg)
 
-[Unreleased]: https://github.com/level/deferred-leveldown/compare/v4.0.2...HEAD
+[Unreleased]: https://github.com/level/deferred-leveldown/compare/v5.0.0...HEAD
+[5.0.0]: https://github.com/level/deferred-leveldown/compare/v4.0.2...v5.0.0
 [4.0.2]: https://github.com/level/deferred-leveldown/compare/v4.0.1...v4.0.2
 [4.0.1]: https://github.com/level/deferred-leveldown/compare/v4.0.0...v4.0.1
 [4.0.0]: https://github.com/level/deferred-leveldown/compare/v3.0.0...v4.0.0

UPGRADING.md

@@ -2,6 +2,10 @@
 
 This document describes breaking changes and how to upgrade. For a complete list of changes including minor and patch releases, please refer to the [changelog](CHANGELOG.md).
 
+## v5
+
+ Upgraded `abstract-leveldown` to `v6.0.0`. Please see the corresponding [changelog entry](https://github.com/Level/abstract-leveldown/blob/master/CHANGELOG.md#600---2018-10-20) for more information.
+
 ## v4
 
 Dropped support for node 4. No other breaking changes.