Activate Travis CI for the project.
Install the Protocol Buffer library dependency before building.
Install the Protocol Buffer compiler dependency before building.
Install a g++ compiler new enough to support the C++11-era language.
Add an APT repository that provides g++ version 4.8.
Force use of the newly installed g++ version by way of setting an
environment variable, as opposed to using update-alternatives.
Provide a Travis CI status image in the README file.