Retrieve all author's metadata from contributors.yml (#1720)
Retrieve all author's metadata from contributors.yml (#1720)

* Retrieve all author's metadata from contributors.yml

Retrieve the information of the author of a blog post from `contributors.yml`
if the author's website is unknow we fallback on their github page.

* Retrieve all author's metadata from contributors, cleaner way to display author's url

* Update post url,  assigns doesn't work with more than one filter

doomspork/elixir-school,doomspork/elixir_school,doomspork/elixir_school,nscyclone/elixir-school,doomspork/elixir-school,doomspork/elixir-school,nscyclone/elixir-school,nscyclone/elixir-school,nscyclone/elixir-school,doomspork/elixir_school