Add version info in dependencies list

Author: samuell

README.md

@@ -71,8 +71,9 @@ minutes.
 Dependencies
 ------------
 
-- [Semantic MediaWiki Extension](http://www.mediawiki.org/wiki/Extension:Semantic_MediaWiki) 2.4.x
-- [The ARC2 RDF library for PHP](https://github.com/semsol/arc2)
+- [MediaWiki](mediawiki.org) 1.26.x (Up to 1.28.x if installing manually. Composer has problems after 1.26)
+- [Semantic MediaWiki Extension](http://www.mediawiki.org/wiki/Extension:Semantic_MediaWiki) 2.4.x (2.5.x won't work yet!)
+- [The ARC2 RDF library for PHP](https://github.com/semsol/arc2) Latest version on github should work
 
 Known limitations
 -----------------