admin switch: Support switching remotes as well

Say I have an installation from CDROM; the remote name may be
"installmedia" or something like that.  We want to allow also
switching remotes.

tests/test-admin-deploy-switch.sh

@@ -27,7 +27,7 @@ setup_os_repository "archive-z2" "syslinux"
 
 echo "ok setup"
 
-echo "1..2"
+echo "1..3"
 
 ostree --repo=sysroot/ostree/repo remote add --set=gpg-verify=false testos file://$(pwd)/testos-repo
 ostree --repo=sysroot/ostree/repo pull testos testos/buildmaster/x86_64-runtime
@@ -42,3 +42,11 @@ ostree admin --sysroot=sysroot switch --os=testos testos/buildmaster/x86_64-deve
 assert_file_has_content sysroot/ostree/deploy/testos/current/usr/include/foo.h 'header'
 
 echo "ok switch"
+
+ostree --repo=sysroot/ostree/repo remote add --set=gpg-verify=false anothertestos file://$(pwd)/testos-repo
+ostree admin --sysroot=sysroot switch --os=testos anothertestos:testos/buildmaster/x86_64-devel
+# Ok this is lame, need a better shell command to extract config, or switch to gjs
+ostree admin --sysroot=sysroot status > status.txt
+assert_file_has_content status.txt anothertestos
+
+echo "ok switch remotes"