Use Travis container-based infrastructure
Use Travis container-based infrastructure

This option add a few restrictions (in particular `sudo` is disabled)
but makes the process quicker to start and to execute.

AlexanderS/wekan,oliver4u/WEKAN_runpartner,ddanssaert/wekan,wykeith/cp2m,johnleeming/wekan,wangdeshui/wekan,johnleeming/wekan,xuxingfan/wekan,AdrianoCahete/wekan,jtickle/wekan,TribeMedia/wekan,wekan/wekan,ndarilek/wekan,chrootsu/wekan,Zyko0/wekan,nztqa/wekan,GhassenRjab/wekan,fisle/wekan,araczkowski/paczka.pro,ddanssaert/wekan,oliver4u/sap-wekan,pro-to-tip/wekan,Zyko0/wekan,nztqa/wekan,ndarilek/wekan,felipecosta07/js,mario-orlicky/wekan,Serubin/wekan,wangdeshui/wekan,wykeith/cp2m,wekan/wekan,Serubin/wekan,wekan/wekan,johnleeming/wekan,MickyBlue/wekan,floatinghotpot/wekan,ketanbhatt/wekan,iu2fish/wekan,ahmadassaf/libreboard,floatinghotpot/wekan,AlexanderS/wekan,samtechie/wekan,GhassenRjab/wekan,TribeMedia/wekan,assarbad/wekan,Xperterra/wekan,libreboard/libreboard,umeshrs/wekan,wekan/wekan,fisle/wekan,nztqa/wekan,evdevgit/wekan,atFriendly/wekan,ddanssaert/wekan,iu2fish/wekan,gelojavonitalla/wekan,oliver4u/sap-wekan,libreboard/libreboard,oliver4u/WEKAN_runpartner,jimmiebtlr/wekan,GhassenRjab/wekan,MickyBlue/wekan,araczkowski/paczka.pro,FSFTN/Wekan,Serubin/wekan,jtickle/wekan,umeshrs/wekan,ahmadassaf/libreboard,gelojavonitalla/wekan,mario-orlicky/wekan,oliver4u/sap-wekan,johnleeming/wekan,ahmadassaf/libreboard,evdevgit/wekan,chrootsu/wekan,jtickle/wekan,atFriendly/wekan,assarbad/wekan,jimmiebtlr/wekan,araczkowski/paczka.pro,samtechie/wekan,wekan/wekan,FSFTN/Wekan,oliver4u/WEKAN_runpartner,felipecosta07/js,ketanbhatt/wekan,pro-to-tip/wekan,mario-orlicky/wekan,Xperterra/wekan,AdrianoCahete/wekan,xuxingfan/wekan