ebextensions: yum does not install package

I am trying to make an ebextensions file which will install wkhtmltopdf.

Currently it looks like this:

packages: 
 yum:
  xorg-x11-fonts-75dpi: []
  libpng: []
  xz: [] 
  urw-fonts: []
  libXext: []
  openssl-devel: []
  libXrender: []
rpm:
   wkhtmltopdf: http://ift.tt/1aH6wW3

In this case, wkthmltopdf fails to install. I get the following error:

Failed dependencies:
  xorg-x11-fonts-75dpi is needed by wkhtmltox-1:0.12.2.1-1.x86_64

If I use SSH to connect to my EC2 instance, I can sucessfully install wkhtml by manually running "yum install xorg-x11-fonts-75dpi", followed by "wget wkthmltopdf-..." and "rpm --install wkhtmltopdf-..". If I skip the yum step, rpm complains that wkhtmltopdf needs the xorg package.

It seems like xorg-x11-fonts-75dpi is not installed by ebextensions on deploy. Am I doing something wrong?