Sage 9.0.0-alpha.4

• Use new webpack api schema (8ac5f15)
• Update dependencies (70ebba7)
• Variables organization (8ac5f15)
• Use $.fn.ready() (reverts 724d550) (e7fccbe)
• Theme activation updates 'stylesheet' option instead of 'template' (fb19145)
• Reorganize and refactor build routine (8c9ba05)
• Switch assets manifest plugin (c1bb2b3)
• Add images to assets manifest (c49793c)
• Switch from babel to buble (0d38ab8)
• Update dependencies & webpack compatibility (BREAKING CHANGES) (eae52fd)
• Use http by default (not https) to be consistent with Trellis (e6f2f49)