Bump version to 0.20
Bump version to 0.20

mrGeen/cython,c-blake/cython,mcanthony/cython,encukou/cython,acrispin/cython,mrGeen/cython,achernet/cython,JelleZijlstra/cython,fperez/cython,dahebolangkuan/cython,scoder/cython,slonik-az/cython,da-woods/cython,hhsprings/cython,fperez/cython,da-woods/cython,dahebolangkuan/cython,dahebolangkuan/cython,hhsprings/cython,andreasvc/cython,cython/cython,fperez/cython,fabianrost84/cython,mcanthony/cython,ABcDexter/cython,encukou/cython,fperez/cython,andreasvc/cython,slonik-az/cython,encukou/cython,marscher/cython,andreasvc/cython,hhsprings/cython,roxyboy/cython,fperez/cython,marscher/cython,mcanthony/cython,achernet/cython,cython/cython,madjar/cython,slonik-az/cython,acrispin/cython,madjar/cython,da-woods/cython,ChristopherHogan/cython,fabianrost84/cython,madjar/cython,encukou/cython,achernet/cython,ABcDexter/cython,acrispin/cython,slonik-az/cython,cython/cython,roxyboy/cython,JelleZijlstra/cython,roxyboy/cython,cython/cython,dahebolangkuan/cython,roxyboy/cython,mcanthony/cython,acrispin/cython,da-woods/cython,slonik-az/cython,hhsprings/cython,andreasvc/cython,c-blake/cython,dahebolangkuan/cython,achernet/cython,fabianrost84/cython,hickford/cython,ABcDexter/cython,hhsprings/cython,mrGeen/cython,ChristopherHogan/cython,JelleZijlstra/cython,hickford/cython,hickford/cython,acrispin/cython,marscher/cython,roxyboy/cython,mrGeen/cython,hickford/cython,madjar/cython,ABcDexter/cython,JelleZijlstra/cython,ChristopherHogan/cython,JelleZijlstra/cython,achernet/cython,scoder/cython,scoder/cython,fabianrost84/cython,mcanthony/cython,andreasvc/cython,madjar/cython,c-blake/cython,encukou/cython,ABcDexter/cython,mrGeen/cython,scoder/cython,marscher/cython,fabianrost84/cython,c-blake/cython,hickford/cython,c-blake/cython,marscher/cython