test fails at certain times of the day

[matthewmueller]

Need to be more explicit with this test case:

describe('parse context if its a string (fixes: #38)', function () {
  it('string context', function () {
    var today = new Date();
    var date = parse('today at 11', "yesterday");
    assert(d(date) == d(today));
    assert('11:00:00' == t(date));
  });
});