Update POSS3

* Fix bug POSS3.transaction, case: no credit
* Add test for bug fixed
* Make POSS3.getImage64 return a simple String
Merge branch 'master' of github.com:trecouvr/server into POSS3
Merge pull request #196 from mattgu74/191

fix #191 - Update the app_lastuse field, on application connection
Merge pull request #197 from trecouvr/POSS3

Poss3
Tout le monde peut consulter ces propres applications
Tentative de test du service KEY
Try to fix travis
Fix error in service KEY
Error in service KEY
Fix the key test
Test app_lastuse + loginApp