Bump version to 0.6.1.
Bump version to 0.6.1.

wraziens/PyMySQL,yeyinzhu3211/PyMySQL,xjzhou/PyMySQL,methane/PyMySQL,jwjohns/PyMySQL,NunoEdgarGub1/PyMySQL,mosquito/Tornado-MySQL,aio-libs/aiomysql,lzedl/PyMySQL,boneyao/PyMySQL,eibanez/PyMySQL,modulexcite/PyMySQL,jheld/PyMySQL,Geoion/Tornado-MySQL,MartinThoma/PyMySQL,eibanez/PyMySQL,xjzhou/PyMySQL,nju520/PyMySQL,wraziens/PyMySQL,PyMySQL/Tornado-MySQL,PyMySQL/PyMySQL,anson-tang/PyMySQL,Ting-y/PyMySQL,lzedl/PyMySQL,yeyinzhu3211/PyMySQL,pulsar314/Tornado-MySQL,DashaChuk/PyMySQL,pymysql/pymysql