Add deploy step to kill previous instances of mojo container.

deployments/mojo.yml

@@ -8,5 +8,7 @@
     command: cd ~/mojojojo-bot && git pull
   - name: Build from the latest version
     command: cd ~/mojojojo-bot && docker build -t mojo -f docker/dockerfile .
+  - name: Check if there are any existing mojo containers running and kill it
+    command: docker ps | grep 'mojo' | awk '{print $1}' | xargs docker kill
   - name: Run the newly built docker container
     command: docker container run -e "SLACK_BOT_TOKEN={{ VAULT_SLACK_BOT_TOKEN }}" --restart "always" -d mojo