move custom REDIS_HOST from Dockerfile to compose

We now use an explicit env var in the compose file. This should make it more clear which hostname the api will try to connect to.

docker-compose.yml

@@ -5,6 +5,8 @@ services:
     build:
       context: jikan
       dockerfile: Dockerfile
+    environment:
+      - REDIS_HOST=jikan-redis
     depends_on:
       - jikan-redis
     ports:

jikan/Dockerfile

@@ -18,7 +18,7 @@ RUN	git clone https://github.com/jikan-me/jikan-rest.git -b v3 . \
 	&& composer update jikan-me/jikan
 
 RUN	sed    -i "s/CACHE_DRIVER=.*/CACHE_DRIVER=redis/" .env \
-	&& sed -i "s/REDIS_HOST=.*/REDIS_HOST=jikan-redis/" .env \
+	&& sed -i "s/REDIS_HOST=.*/REDIS_HOST=redis/" .env \
 	&& sed -i "s/CACHE_404_EXPIRE=.*/CACHE_404_EXPIRE=3600/" .env \
 	&& sed -i "s/CACHE_SEARCH_EXPIRE=.*/CACHE_SEARCH_EXPIRE=1000/" .env \
 	&& sed -i "s/GITHUB_REPORTING=.*/GITHUB_REPORTING=false/" .env