The iOS keychain plugin is not being properly installed.  The <plugin>
entries are not being added to Cordova.plist after pluginstall is
run.  (The plugins .m and .h artifacts do seem to be properly included.)

I have added the entries to the template, so they're present always, but
the plugin is still not working right.

.setForKey() succeeds with "OK", but .getForKey fails, with the
failcallback conveying:

  error retrieving value for key 'test' : (null)