Add Melissa Staging email address for testing

[holytoastr]

Summary

• Need an email address that can be used to log into Flipper staging sandbox for testing. This is to get around an issue with a broken idme account that won't allow me to log in.
• Have confirmed I can log in with this idme account
• Login Adoption Team

Related issue(s)

N/A

Testing done

N/A

Screenshots

N/A

What areas of the site does it impact?

• Adds access to Flipper admin panel on staging

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog or Grafana (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature

Requested Feedback

(OPTIONAL)What should the reviewers know in addition to the above. Is there anything specific you wish the reviewer to assist with. Do you have any concerns with this PR, why?

[ryan-mcneil]

I'm currently working on a way for us manage Flipper Authorization through Github Teams instead of this file. Stay Tuned 😃