fixes install target, adds travis badge, invokes make test

edit README.md
 * adds travis status badge

edit Makefile
 * fixes install target to depend on youtube-dl.fish
 * fixes README.md target to invoke youtube_dl compliant with python-2.6

edit .travis.yml
 * adds pre-install verbosity
 * pandoc installation
 * make, make test, sudo make install,
Github projects serviced by Travis-CI commonly include this build badge at the top of the README.md. For visitors to the repo page, it provides an intuitive and coherent visual cue to the health of the project. If the README.md file is serving as a template for other other artifacts, then this is inappropriate---I'll have to remove the badge.