Merge pull request #6453 from gitlabhq/link-to-dot-com

Link to consolidated website with https links. Fixes #6017

app/views/shared/_promo.html.haml

 .gitlab-promo
-  = link_to "Homepage", "http://gitlab.org"
-  = link_to "Blog", "http://blog.gitlab.org"
+  = link_to "Homepage", "https://www.gitlab.com/"
+  = link_to "Blog", "https://www.gitlab.com/blog/"
   = link_to "@gitlabhq", "https://twitter.com/gitlabhq"