changelog updated

CHANGELOG.md

 # Changelog
 
+## 1.3.11 (2020-02-14)
+
+### New Features
+- A new set of tests for CI to verify the consistency of results during changes has been
+  implemented.
+- Test and reference files have been created and added to the repository.
+- The code has been cleaned up of all the unused parts.
+- New, simplified tools for writing output files have been created to replace the old
+  ioutils.
+
+### Fixed Bugs
+- Solved fill value issue #24. Default fill value changed to -9999
+- `--verbose` mode in `yori-grid` has been completely removed since it is not useful
+  anymore
+
+
 ## 1.3.10 (2019-09-12)
 
 ### Fixes