Add a warning for OSX 10.9

[mpapis]

Currently we do not have a version for OSX 10.9 and users should not try to use older versions on it, we should instead advertise:

\curl -sSL https://get.rvm.io | bash -s stable --rails

It will download RVM, Ruby, Ruby on Rails and take care of all dependencies, maybe it's not as good as a single download installer but should be a lot better then osx-gcc-installer problems mentioned railsinstaller/railsinstaller-nix#19 (comment) or Homebrew/legacy-homebrew#25249

[mistydemeo]

Please also make the installer refuse to install on 10.9 - that would eliminate a lot of potential issues too.

[MikeMcQuaid]

Agreed.

[mpapis]

the suggestions for installer itself fit more to railsinstaller/railsinstaller-nix#19 or even separate ticket

[emachnic]

@mpapis I think the warning is good and I also like @mistydemeo's idea if that were possible. On a similar note, we did actually get the Apple developer license if you want to put this in your backlog.

[MikeMcQuaid]

@mpapis Well we're been asking you to stop using osx-gcc-installer at all in railsinstaller/railsinstaller-nix#19 for a very long time and you haven't commented there for two months.

@emachnic It is perfectly possible, it's software after all. It's just a question of if and when it gets done and whether this software which is breaking users systems is fixed or not.

[mistydemeo]

Filed railsinstaller/railsinstaller-nix#26 for the installer.

[mtheoryx]

Doesn't xcode-select --install take care of any CLI dev tools issues?