fix(icon): init `_icon` property properly
fix(icon): init `_icon` property properly

rolandjitsu/ng2-lab,rolandjitsu/angular-lab,rolandjitsu/angular-lab,rolandjitsu/ng2-play,rolandjitsu/ng2-play,rolandjitsu/ng2-lab,rolandjitsu/ng2-play,rolandjitsu/angular-lab,rolandjitsu/ng2-lab,rolandjitsu/ng2-play,rolandjitsu/angular-lab,rolandjitsu/ng2-lab