Upgrade ES in CI to 7.11.1 to match production

At present we are running `7.11.0` in production. This is the closest
version and having CI closer to production is preferable.

.gitlab/ci/global.gitlab-ci.yml

@@ -102,7 +102,7 @@
     - name: postgres:11.6
       command: ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off", "-c", "full_page_writes=off"]
     - name: redis:5.0-alpine
-    - name: elasticsearch:7.10.1
+    - name: elasticsearch:7.11.1
       command: ["elasticsearch", "-E", "discovery.type=single-node"]
   variables:
     POSTGRES_HOST_AUTH_METHOD: trust
@@ -113,7 +113,7 @@
     - name: postgres:12
       command: ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off", "-c", "full_page_writes=off"]
     - name: redis:5.0-alpine
-    - name: elasticsearch:7.10.1
+    - name: elasticsearch:7.11.1
       command: ["elasticsearch", "-E", "discovery.type=single-node"]
   variables:
     POSTGRES_HOST_AUTH_METHOD: trust