Remove files block from assets/package.json
Remove files block from assets/package.json

The assets package shouldn't be used as a depedency so there is no need
for the `files` key to be used.

https://docs.npmjs.com/files/package.json#files

keathley/phoenix,rafbgarcia/phoenix,evax/phoenix,evax/phoenix,mschae/phoenix,0x00evil/phoenix,0x00evil/phoenix,mitchellhenke/phoenix,michalmuskala/phoenix,pap/phoenix,mitchellhenke/phoenix,rafbgarcia/phoenix,mobileoverlord/phoenix,jwarwick/phoenix,keathley/phoenix,rafbgarcia/phoenix,dmarkow/phoenix,nshafer/phoenix,pap/phoenix,eksperimental/phoenix,Joe-noh/phoenix,phoenixframework/phoenix,jwarwick/phoenix,Kosmas/phoenix,optikfluffel/phoenix,optikfluffel/phoenix,Gazler/phoenix,mschae/phoenix,eksperimental/phoenix,0x00evil/phoenix,michalmuskala/phoenix,phoenixframework/phoenix,nshafer/phoenix,dmarkow/phoenix,nshafer/phoenix,optikfluffel/phoenix,Kosmas/phoenix,phoenixframework/phoenix,Gazler/phoenix,Joe-noh/phoenix,mobileoverlord/phoenix