yesterdayjs v0.0.2

#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