Merge pull request #2 from zotya/master

Fixed tests for eea.sparql
Set default values for column_types and annotations
Refs #9608; Updated wording for query preview
Updated version for eea.sparql to 2.5-dev
Fix homepage URL
Added information for contributors

* Feature: added information for contributors
[ciobabog refs #13892]
Refs #14349; Fixed preview for sparql queries when arguments are missing