[py] bump version to 0.6.1
[py] bump version to 0.6.1

Zirpon/tchannel,savaki/tchannel,Zirpon/tchannel,benfleis/tchannel,vanloswang/tchannel,vanloswang/tchannel,Zirpon/tchannel,i/tchannel,benfleis/tchannel,savaki/tchannel,hustxiaoc/tchannel,benfleis/tchannel,chenwenbin928/tchannel,RyanTech/tchannel,hustxiaoc/tchannel,RyanTech/tchannel,i/tchannel,bunnyblue/tchannel,sasa233/tchannel,chenwenbin928/tchannel,bunnyblue/tchannel,savaki/tchannel,sasa233/tchannel,i/tchannel,vanloswang/tchannel,chenwenbin928/tchannel,RyanTech/tchannel,sasa233/tchannel,bunnyblue/tchannel,hustxiaoc/tchannel