using builds to generate pdf from latex source (nearly there)

we use gitlab in our research group (as probably many others) to write scientific papers together in latex...

with the awesome integration of gitlab ci and the runners 👍 the following .gitlab-ci.yml nearly gets you all the way so you never have to commit the PDF again or worry that you forgot to commit some graphic, etc., by simply having a runner generate it:

compile_pdf:
  image: tianon/latex
  script:
    - latexmk -pdf paper.tex
  artifacts:
    paths:
      - paper.pdf

Now the two tiny things i can't figure out are:

• how to provide a link to the pdf instead of the artifacts.tgz
• and how to get the latest build for a branch like master so i can put a "latest version" pdf permalink in the README

Any ideas what i'm missing? Or is this maybe not possible yet?