Add test that checks that a session close event sent by the application worker is honoured.
Add test that checks that a session close event sent by the application worker is honoured.

harrissoerja/vumi,vishwaprakashmishra/xmatrix,harrissoerja/vumi,vishwaprakashmishra/xmatrix,harrissoerja/vumi,vishwaprakashmishra/xmatrix,TouK/vumi,TouK/vumi,TouK/vumi