Prepare version 0.11.4 (#181)

* Prepare version 0.11.4

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -1,8 +1,10 @@
 # Changelog
 
-## Version 0.11.4 (in preparation)
+## Version 0.11.4 (2021-08-23)
 
-* Miscellaneous:
+* CI and tests:
+  - Run the CI on Linux, MacOS and Windows (#179)
+  - Re-added coverage tests replacing Coveralls with Codecov.
   - Removed Azure pipelines since superseded by GitHub Actions.
 
 ## Version 0.11.3 (2021-07-28)