Fixing STORM-1193
Fixing STORM-1193

Resolves "Class "SimplePollingSensor" doesn't implement required "update_trigger" method from the base class" error when running sensor using "st2sensorcontainer --config-file=/etc/st2/st2.conf --sensor-name=SimplePollingSensor"
dennybaa/st2,Plexxi/st2,grengojbo/st2,emedvedev/st2,alfasin/st2,Plexxi/st2,jtopjian/st2,alfasin/st2,Plexxi/st2,tonybaloney/st2,pixelrebel/st2,armab/st2,tonybaloney/st2,pinterb/st2,peak6/st2,StackStorm/st2,StackStorm/st2,armab/st2,dennybaa/st2,StackStorm/st2,emedvedev/st2,lakshmi-kannan/st2,emedvedev/st2,lakshmi-kannan/st2,pinterb/st2,nzlosh/st2,punalpatel/st2,Plexxi/st2,pixelrebel/st2,nzlosh/st2,pixelrebel/st2,Itxaka/st2,armab/st2,peak6/st2,grengojbo/st2,pinterb/st2,jtopjian/st2,tonybaloney/st2,jtopjian/st2,peak6/st2,punalpatel/st2,punalpatel/st2,grengojbo/st2,dennybaa/st2,nzlosh/st2,lakshmi-kannan/st2,StackStorm/st2,alfasin/st2,nzlosh/st2,Itxaka/st2,Itxaka/st2