The app never removes old sessions data in ~/.cache/<app-name>

[Sylvain Pineau]

Even after finishing a session and starting a new testrun, I can see the old sessions folders in:

~/.cache/com.canonical.certification.checkbox-touch

phablet@ubuntu-phablet:~/.cache/com.canonical.certification.checkbox-touch$ ll
total 32
drwxrwxr-x 7 phablet phablet 4096 Nov 27 20:02 ./
drwx------ 20 phablet phablet 4096 Nov 27 19:50 ../
drwx------ 3 phablet phablet 4096 Nov 27 20:01 pbox-75d7k94o.session/
drwx------ 3 phablet phablet 4096 Nov 27 19:51 pbox-byzgcvjd.session/
drwx------ 3 phablet phablet 4096 Nov 27 20:02 pbox-fl9d0lop.session/
drwx------ 3 phablet phablet 4096 Nov 27 19:51 pbox-tq592_8w.session/
drwx------ 3 phablet phablet 4096 Nov 27 19:50 pbox-w34dgi8v.session/
-rw-rw-r-- 1 phablet phablet 13 Nov 27 20:02 session_id

The app should delete the session data when the testrun is over