Fixup Loki monitoring mixin (#248)

* Fix the mixin to reference the mixin-utils pkg.

Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>

* s/g.selector/utils.selector/

Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>

* Actually import utils.

Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>

* Don't cut corners with replacing.

Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>