bump podspec to 0.3.1
bump podspec to 0.3.1

rromanchuk/PBJVision,Bijiabo/PBJVision,sebyddd/PBJVision,zuoguoqing/PBJVision,piemonte/PBJVision,denivip/PBJVision,rFlex/PBJVision,Maciej-Matuszewski/PBJVision,jonesgithub/PBJVision,shiflymoon/PBJVision,shenyuan000/PBJVision,yunarta/PBJVision,gary109/PBJVision,medvedNick/PBJVision,jvk75/PBJVision,Raztor0/PBJVision,aaronsakowski/PBJVision