Tests and fixes

- added two feeds for testing purposes;
- added tests for parsing these (and future) feeds;
- removed AtomLink which does not work due to a known bug in Go
(https://codereview.appspot.com/6868044);
- added an option to parse date with arbitrary time;
Merge pull request #1 from marcinwyszynski/tests

We really need tests.
Merge pull request #5 from marcinwyszynski/master

Add tests plus minor fixes