Update change-log.md

change-log.md

 # Change Log
 
+## 30 June 2022: V 0.2.7
+
+### New or Improved Functionality: 
+* Importing and deleting generator definitions has been improved;
+* Minor updates in the content of some emails sent by the system to users;
+* Resetting the contents of the RDF Visualizer's dialog every time it is opened;
+* Several minor UI improvements;
+
+### Bug Fixes:
+* Resolving issue with not sending (through email) user's credential when requested;
+* Resolving all issues with deleting groups and group-sets, affecting the contained mappings;
+
 ## 16 June 2022: V 0.2.6
 
 ### Bug Fixes: