Remove module-level vumi.application.session deprecation.
Remove module-level vumi.application.session deprecation.

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