Make OCTPlan properties readonly
Make OCTPlan properties readonly

GroundControl-Solutions/octokit.objc,CHNLiPeng/octokit.objc,xantage/octokit.objc,leichunfeng/octokit.objc,cnbin/octokit.objc,daemonchen/octokit.objc,CHNLiPeng/octokit.objc,wrcj12138aaa/octokit.objc,Palleas/octokit.objc,1234-/octokit.objc,wrcj12138aaa/octokit.objc,daukantas/octokit.objc,Acidburn0zzz/octokit.objc,yeahdongcn/octokit.objc,Acidburn0zzz/octokit.objc,xantage/octokit.objc,jonesgithub/octokit.objc,phatblat/octokit.objc,cnbin/octokit.objc,jonesgithub/octokit.objc,GroundControl-Solutions/octokit.objc,1234-/octokit.objc,daukantas/octokit.objc,CleanShavenApps/octokit.objc,phatblat/octokit.objc,daemonchen/octokit.objc,leichunfeng/octokit.objc,Palleas/octokit.objc