kube: clean up SimpleIngress

Rename `target_service` to `target` to mirror Service's `target`; rename `extra_paths` to `extraPaths` to follow the camelCase convention used everywhere except for a few places in kube.upstream (assumed to be a mistake)

Change-Id: Icfcb70ef889e3359bf0391c465034817f4b70cce
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1809
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/personal/q3k/rc3.jsonnet b/personal/q3k/rc3.jsonnet
index b4112f2..3d2d351 100644
--- a/personal/q3k/rc3.jsonnet
+++ b/personal/q3k/rc3.jsonnet
@@ -37,6 +37,6 @@
             namespace: "personal-q3k",
         },
         hosts:: ["rc3-data.q3k.org"],
-        target_service:: rc3.svc,
+        target:: rc3.svc,
     },
 }