chore(package): update shower-core to version 2.0.6
chore(package): update shower-core to version 2.0.6

http://greenkeeper.io/
rakchaev/offline_frontend-mix2016,zolotyh/spa-pres,rakchaev/offline_frontend-mix2016,AnalogJ/capsulecd-slides,belbiy/eugene-intro,belbiy/eugene-intro,CaraWang/2016-talk-cnyes-elasticsearch,Robsteranium/grafting-linked-data-slides,zolotyh/spa-pres,AnalogJ/capsulecd-slides,CaraWang/2016-talk-cnyes-elasticsearch,easy-deep-learning/event-emitter,easy-deep-learning/event-emitter,rakchaev/assembly-pyatnica2016,rakchaev/assembly-pyatnica2016,Robsteranium/grafting-linked-data-slides