Updated Rails version support in readme.
Updated Rails version support in readme.

Refinery 3.0.0 will only work on Rails 4.1+

Also fixed the branch for coveralls.

[ci skip]
anitagraham/refinerycms,stefanspicer/refinerycms,sideci-sample/sideci-sample-refinerycms,refinery/refinerycms,johanb/refinerycms,trevornez/refinerycms,trevornez/refinerycms,kappiah/refinerycms,johanb/refinerycms,refinery/refinerycms,LytayTOUCH/refinerycms,Eric-Guo/refinerycms,mkaplan9/refinerycms,aguzubiaga/refinerycms,aguzubiaga/refinerycms,gwagener/refinerycms,gwagener/refinerycms,mabras/refinerycms,bricesanchez/refinerycms,kappiah/refinerycms,KingLemuel/refinerycms,mkaplan9/refinerycms,simi/refinerycms,mlinfoot/refinerycms,refinery/refinerycms,anitagraham/refinerycms,simi/refinerycms,anitagraham/refinerycms,mabras/refinerycms,chrise86/refinerycms,Retimont/refinerycms,hoopla-software/refinerycms,mkaplan9/refinerycms,sideci-sample/sideci-sample-refinerycms,LytayTOUCH/refinerycms,Eric-Guo/refinerycms,johanb/refinerycms,stefanspicer/refinerycms,Retimont/refinerycms,kappiah/refinerycms,chrise86/refinerycms,bricesanchez/refinerycms,LytayTOUCH/refinerycms,KingLemuel/refinerycms,simi/refinerycms,gwagener/refinerycms,hoopla-software/refinerycms,KingLemuel/refinerycms,simi/refinerycms,hoopla-software/refinerycms,aguzubiaga/refinerycms,Retimont/refinerycms,mabras/refinerycms,stefanspicer/refinerycms,Eric-Guo/refinerycms,trevornez/refinerycms,chrise86/refinerycms,mlinfoot/refinerycms,mlinfoot/refinerycms