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,
You're correct; in general, ```__main__``` is implicit---since python 2.7:
 * http://stackoverflow.com/questions/6630822/running-a-python-package
 * https://docs.python.org/2/whatsnew/2.7.html#new-and-improved-modules
 * http://bugs.python.org/issue6816

If you want to python 2.6 (as your .travis.yml suggests) then this change is necessary.