Added empty content test for yaml front-matter
Added empty content test for yaml front-matter

jp1017/hexo,liuhongjiang/hexo,xushuwei202/hexo,hexojs/hexo,logonmy/hexo,zhi1ong/hexo,Carbs0126/hexo,zhoulingjun/hexo,sundyxfan/hexo,maominghui/hexo,DanielHit/hexo,ppker/hexo,karenpeng/hexo,runlevelsix/hexo,elegantwww/hexo,DevinLow/DevinLow.github.io,hugoxia/hexo,HcySunYang/hexo,dieface/hexo,wenzhucjy/hexo,JasonMPE/hexo,nextexit/hexo,kennethlyn/hexo,biezhihua/hexo,crystalwm/hexo,k2byew/hexo,hanhailong/hexo,xcatliu/hexo,meaverick/hexo,wyfyyy818818/hexo,viethang/hexo,beni55/hexo,wwff/hexo,registercosmo/hexo,Regis25489/hexo,keeleys/hexo,chenbojian/hexo,delkyd/hexo,aulphar/hexo,noname007/hexo-1,noikiy/hexo,cjwind/hexx,imjerrybao/hexo,allengaller/hexo,lknny/hexo,initiumlab/hexo,SaiNadh001/hexo,memezilla/hexo,BruceChao/hexo,HiWong/hexo,tibic/hexo,Jeremy017/hexo,Richardphp/hexo,sailtoy/hexo,will-zhangweilin/myhexo,oomusou/hexo,liukaijv/hexo,zhipengyan/hexo,luodengxiong/hexo,leelynd/tapohuck,Bob1993/hexo,ChaofengZhou/hexo,0111001101111010/blog,r4-keisuke/hexo,wangjordy/wangjordy.github.io,lookii/looki,xiaoliuzi/hexo,magicdawn/hexo,dreamren/hexo,SampleLiao/hexo,G-g-beringei/hexo,wflmax/hexo,luinnx/hexo,zhipengyan/hexo,tzq668766/hexo,XGHeaven/hexo,0111001101111010/hexo,kywk/hexi,hackjustu/hexo,jonesgithub/hexo,wangjordy/wangjordy.github.io,gaojinhua/hexo,znanl/znanl,DevinLow/DevinLow.github.io,zongkelong/hexo,amobiz/hexo,zoubin/hexo,hexojs/hexo,littledogboy/hexo,kywk/hexi,GGuang/hexo,ppker/hexo,haoyuchen1992/hexo,lukw00/hexo,fuchao2012/hexo,Gtskk/hexo,chenzaichun/hexo,glabcn/hexo,jollylulu/hexo,zhangg/hexo,iamprasad88/hexo,leikegeek/hexo