Use filename 'identity' for all key types.

This is to allow the use of other key types with the -t option.
E.g. -t ed25519

This change is backwards compatible with existing gitnonymous
identities.

gitnonymous

       echo "Done unsetting ${keyname}."
     else
       # add our custom local SSH key (make the key with ./make-anonymous-key)
-      if [ -f ${sshdir}/id_rsa ]
+      if [ -f ${sshdir}/id_rsa -o -f ${sshdir}/identity ]
       then
         # if a stale socket already exists then throw an error
         if [ -f "${sshagentsocket}" ]
         # start a new SSH agent just for this session
         eval $(ssh-agent -a "${sshagentsocket}")
         # add the key
-        ssh-add ${sshdir}/id_rsa
+        if [ -f ${sshdir}/id_rsa ]
+        then
+          ssh-add ${sshdir}/id_rsa
+        else
+          ssh-add ${sshdir}/identity
+        fi
       else
         gitnonymous_error_missing "SSH config in ${sshdir} not found!"
         return 3

gitnonymous-setup

 
 # set up our other variables
 confdir="${HOME}/.gitnonymous-${1}"
-sshfile="${confdir}/ssh/id_rsa"
+sshfile="${confdir}/ssh/identity"
 configfile="${confdir}/config"
 sshwrapperfile="${confdir}/git-ssh-wrap"