Nýr endpoint á beygingum fyrir bin.arnastofnun.is

This commit fixes #73 - there is only one endpoint, declension/:word (http://translate.google.com/#auto/en/fallbeyging), it takes in a given word and returns the permutations of said word, with its (icelandic: fall, tölu and kyn) - i havent written anything other than just the code and integration test, if this is not the solution you were looking for please comment on that and i will fix it, otherwise i will add documentation as soon as the pull request is accepted.