Fix missing redis server to gitpod configuration (#5528)

.gitpod.dockerfile

@@ -2,5 +2,10 @@ FROM gitpod/workspace-postgres
 
 # Install Ruby
 ENV RUBY_VERSION=2.6.5
-RUN bash -lc "rvm install ruby-$RUBY_VERSION && rvm use ruby-$RUBY_VERSION --default" \
- && rm -f /tmp/*
+RUN bash -lc "rvm install ruby-$RUBY_VERSION && rvm use ruby-$RUBY_VERSION --default"
+
+# Install Redis.
+RUN sudo apt-get update \
+ && sudo apt-get install -y \
+  redis-server \
+ && sudo rm -rf /var/lib/apt/lists/*

.gitpod.yml

@@ -7,7 +7,10 @@ ports:
     onOpen: ignore
   - port: 5432
     onOpen: ignore
+  - port: 6379
+    onOpen: ignore
 tasks:
+  - command: redis-server
   - init: >
       cp config/sample_application.yml config/application.yml &&
       bin/setup 2>/dev/null || true