Upgrade to local node:10.18.1 image

services/clsi/Dockerfile

@@ -1,4 +1,4 @@
-FROM node:10.15.0 as app
+FROM gcr.io/overleaf-ops/node:10.18.1 as app
 
 WORKDIR /app
 
@@ -12,7 +12,7 @@ COPY . /app
 
 RUN npm run compile:all
 
-FROM node:10.15.0
+FROM gcr.io/overleaf-ops/node:10.18.1
 
 COPY --from=app /app /app