Updated CouchDB image to 2.3 (#257)

diff --git a/docker-compose/docker-compose.yml b/docker-compose/docker-compose.yml
index a9d6977..7f0f55b 100644
--- a/docker-compose/docker-compose.yml
+++ b/docker-compose/docker-compose.yml
@@ -3,7 +3,7 @@
 version: '3'
 services:
   db:
-    image: apache/couchdb:2.1
+    image: apache/couchdb:2.3
     ports:
       - "5984:5984"
     environment: