App: Delete User

Give the User the option to delete their own account. This is a requirement to submit an app because it gives users a way to take control of their data.

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Acceptance criteria:

* [ ] make a red text button at the bottom at the homepage that says 'delete user'
* [ ] When a user clicks on it, give them a popup that says "are you sure you want to delete your account" with a textfield that says Delete
* [ ] If they type delete and hit submit, LOG THE USER OUT, then trigger a cloud function that deletes the user's account based off of the UID they had. Make sure to test it yourself, because shenanigans can happen when the implementation is confused between current user information and deleted information.