Add flash messages to homepage

[lisavogtsf]

Context

• Fixes #[issueNumber]
• short_summary_here

Summary of Changes

• change_1_here
• change_2_here

Checklist

• [ ] Tested Mobile Responsiveness
• [ ] Added Unit Tests
• [ ] CI Passes
• [ ] Deploys to Heroku on test Correctly (Maintainers will handle)
• [ ] Added Documentation (Service and Code when required)

Screenshots

Before

After

[lisavogtsf]

This code is going to be incorporated as part of the Ruby by the Bay PR