It can take a while to build a lsst-texmf document on Travis CI. The trouble is that we're installing a full texlive every time. It might be more efficient to download a Docker image with texlive pre-installed and run the latex build from that container.
One question is whether to include lsst-texmf or not with the image. I think it may be wise to create a base image without lsst-texmf since some projects will include lsst-texmf as a submodule. Then a second Docker image, with a Dockerfile in the lsst-texmf project, can layer lsst-texmf upon that.