Bump version to 0.3.0
Bump version to 0.3.0

danburkert/mio,echochamber/mio,bottompawn/mio,rryan/mio,rrichardson/mio,fuchsia-mirror/third_party-mio,dpc/mio,marjakm/mio,thijsc/mio,carllerche/mio,asomers/mio,luca-barbieri/mio,fhartwig/mio,arthurprs/mio,fuchsia-mirror/third_party-mio,asomers/mio,mneumann/mio,greensnark/mio,mneumann/mio,yuikns/mio,murarth/mio,carllerche/mio,yangxingpping/mio,tailhook/mio,tempbottle/mio,mlalic/mio,zslayton/mio,frewsxcv/mio,geofft/mio,pythonesque/mio,dwrensha/mio,hjr3/mio,alexcrichton/mio