upgrade gems as needed to support jekyll 1.5.0
move folder weights into site.data
move folder_icons to site.data
add data assets
move breadcrumb list to data
move version to data
remove unneeded comment
add new data assets
configure travis to automatically add build info to version number
Merge pull request #346 from sendgrid/upgrade

Upgrade jekyll to 1.5.0, move metadata from _config.yml to _data folder