Updated release notes

Author: rijnb

src/site/markdown/ReleaseNotes.md

@@ -4,6 +4,8 @@ These are the release notes for the Java library for mapcodes.
 
 ### 2.4.1
 
+* Removed secret Coveralls key from POM file.
+ 
 * Added scripts for Tifinagh (Berber), Tamil, Amharic, Telugu, Odia, Kannada, Gujarati.
 
 * Added `getAlphabets()` to `Territory` class, returning the most commonly used languages for the territory.