Build requires commands from .travis.yml before snapcraft works

[basak]

Some pre-setup is done in .travis.yml now, so running just snapcraft on its own doesn't work. It would be nice if the setup were all done in snapcraft so knowledge of the Travis side isn't required to successfully build. This will also enable easier builds in other environments.

Workaround: examine .travis.yml and run those (currently two) commands manually, and then run snapcraft.