[TASK] Prepare release of version 4.0.0 (#877)

[TASK] Prepare release of version 4.0.0

Also move the 3.1.0 change to a separate changelog section.

Closes #874

CHANGELOG.md

@@ -5,6 +5,19 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## x.y.z
 
+### Added
+
+### Changed
+
+### Deprecated
+- Support for PHP 7.1 will be removed in Emogrifier 6.0.
+
+### Removed
+
+### Fixed
+
+## 4.0.0
+
 ### Added
 - Extract and inject `@font-face` rules into head
   ([#870](https://github.com/MyIntervals/emogrifier/pull/870))
@@ -18,8 +31,6 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 - Configuration setting methods now all return `$this` to allow chaining
   ([#824](https://github.com/MyIntervals/emogrifier/pull/824),
   [#854](https://github.com/MyIntervals/emogrifier/pull/854))
-- Add support for PHP 7.4
-  ([#821](https://github.com/MyIntervals/emogrifier/pull/821))
 - Disable php-cs-fixer Yoda conditions
   ([#791](https://github.com/MyIntervals/emogrifier/issues/791),
   [#794](https://github.com/MyIntervals/emogrifier/pull/794))
@@ -51,8 +62,6 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   [#843](https://github.com/MyIntervals/emogrifier/pull/843),
   [#846](https://github.com/MyIntervals/emogrifier/pull/846),
   [#849](https://github.com/MyIntervals/emogrifier/pull/849))
-- Upgrade to Symfony 5.0
-  ([#822](https://github.com/MyIntervals/emogrifier/pull/820))
 - Clean up the folder structure and autoloading configuration
   ([#529](https://github.com/MyIntervals/emogrifier/issues/529),
   [#785](https://github.com/MyIntervals/emogrifier/pull/785))
@@ -89,6 +98,17 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   ([#740](https://github.com/MyIntervals/emogrifier/issues/740),
   [#780](https://github.com/MyIntervals/emogrifier/pull/780))
 
+## 3.1.0
+
+### Added
+- Add support for PHP 7.4
+  ([#821](https://github.com/MyIntervals/emogrifier/pull/821),
+  [#829](https://github.com/MyIntervals/emogrifier/pull/829))
+
+### Changed
+- Upgrade to Symfony 5.0
+  ([#820](https://github.com/MyIntervals/emogrifier/pull/820))
+
 ## 3.0.0
 
 ### Added

README.md

@@ -407,13 +407,13 @@ They will, however, be preserved and copied to a `<style>` element in the HTML:
 
 ## Steps to release a new version
 
-1. Create a pull request "Prepare release of version x.y.z" with the following
-   changes.
 1. In the [composer.json](composer.json), update the `branch-alias` entry to
    point to the release _after_ the upcoming release.
 1. In the [CHANGELOG.md](CHANGELOG.md), create a new section with subheadings
    for changes _after_ the upcoming release, set the version number for the
    upcoming release, and remove any empty sections.
+1. Create a pull request "Prepare release of version x.y.z" with those
+   changes.
 1. Have the pull request reviewed and merged.
 1. Tag the new release.
 1. In the [Releases tab](https://github.com/MyIntervals/emogrifier/releases),

composer.json

@@ -97,7 +97,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "4.0.x-dev"
+            "dev-master": "5.0.x-dev"
         }
     }
 }