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,
Sudo is necessary to install the executable to the default prefixed bin location, i.e., /usr/local/bin. This is a common action for users intending to install the executable to a location already part of the PATH. This is an adaption of the oft-repeated "./configure && make && sudo make install".