Routes: Add `/costs` route

Render the `costs` field of a `Chouette::Route` as JSON. This lives at:
http://stif-boiv.dev:3000/referentials/4/lines/1857/routes/7/costs.json

I want this in order to get the distance & time costs of a route so that
I can merge them with `JourneyPattern#costs` on the frontend on
`JourneyPatternsCollection#show`.

Refs #6203

1 files changed, 2 insertions, 0 deletions

diff --git a/app/views/routes/costs.rabl b/app/views/routes/costs.rabl
new file mode 100644
index 000000000..d4465d03e
--- /dev/null
+++ b/app/views/routes/costs.rabl
@@ -0,0 +1,2 @@
+object @route
+attributes :costs