Having a script that contains default checks could be run before a contributor does a PR:
* checking copyrights are updated
* qsTr() are used
- no Text but GCText
- no temp files
- author name of the commit is "FirstName SecondName"
- each ActivityInfo has qsTr(), createdInVersion and an intro text
...
Check http://gcompris.net/wiki/Reviewing_an_activity and http://gcompris.net/wiki/GSOC_newcomers#Code_quality to see what else could be added and the previous github PR that contains a lot of same comments.