Added podspecs for cocos2d v3.0 release candidates rc3, rc4 and rc5

Previous rc1 and r2 are not supported as the project does not even compile
when checking out the tags for those releases.
Rc3 does not compile: project file is wrong
Add version 3.1.0 alpha

kazmath dependency removed
Merge pull request #11049 from rickyah/feature/add_cocos2d_3

Feature/add cocos2d version 3.0 and 3.1