Use keychain instead of .netrc

[nschum]

It would be great if the user's keychain could be used to store credentials instead of the plain-text .netrc file.

[supermarin]

+1

[mattt]

Sure, I can add this in. I may end up writing a Keychain Access library in the process, though—I've looked around for libraries, and the ones I found left a lot to be desired.

[matthiaswenz]

+1

[leobessa]

+1

[mattt]

Happy to report that as of version 0.5.0, Cupertino stores credentials with the keychain, using the Security gem :)