Enable selenium service in devcontainer for system tests (#1340)

Co-authored-by: Pedro J. Aramburu <pedro@joakin.dev>

.devcontainer/devcontainer.json

@@ -4,7 +4,8 @@
   "service": "app",
   "runServices": [
     "db",
-    "redis"
+    "redis",
+    "selenium"
   ],
   "workspaceFolder": "/workspace",
   "containerEnv": {

.devcontainer/docker-compose.yml

@@ -10,6 +10,7 @@ x-rails-env: &rails_env
   POSTGRES_PASSWORD: postgres
   BUNDLE_PATH: /bundle
   REDIS_URL: redis://redis:6379/1
+  SELENIUM_REMOTE_URL: http://selenium:4444
 
 services:
   app:
@@ -28,6 +29,7 @@ services:
     depends_on:
       - db
       - redis
+      - selenium
 
   worker:
     build:
@@ -59,6 +61,14 @@ services:
     environment:
       <<: *db_env
 
+  selenium:
+    image: selenium/standalone-chromium:latest
+    ports:
+      - "4444:4444"
+      - "7900:7900"
+    shm_size: 2gb
+    restart: unless-stopped
+
 volumes:
   postgres-data:
   redis-data: