Don't copy _robots.txt

It's now called `robots.txt` and there is no special handling any longer.

Author: mlocher

Dockerfile.aws

@@ -10,4 +10,4 @@ RUN apk --update add \
 
 WORKDIR /deploy
 COPY bin/jet.sh bin/s3.sh ./bin/
-COPY _lifecycle.json _robots.txt _website.json ./
+COPY _lifecycle.json _website.json ./