Update mix-cowboy1.lock to use plug 1.5.0 and phoenix_html 2.11.0
Update mix-cowboy1.lock to use plug 1.5.0 and phoenix_html 2.11.0

Only the plug and phoenix_html dependencies have been added to prevent
updating to Cowboy 2.

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