#yesterdayJS 0.0.0-- tiny descent JavaScript Date library
##Usage
import yesterday.js in your html
<script tye='text/javascript' src='./yesterday'></script>
Init a yesterday global object
var y = new Yesterday();
call the useful method on y
y.today(); // today date
y.yesterday(); //yesterday date
y.tomorrow(); //tomorrow date
y.future(num); //date of future 'num' days
y.past(num); //date of past 'num' days
y.holiday(); //'我好想dayday都是Saturdayヾ(^ω^*)'
to be continue