Hard-coded admin relays message to hard-coded group members

Acceptance Criteria

GIVEN a channel #red-alert on phone number +1-666-666-6666

• AND a hard-coded admin, alice, of that group with a different phone number
• AND two hard-coded members of that group, bob and cassie (also with different phone numbers)
• WHEN alice sends the signal message "hello world!" to +1-666...
• THEN alice, bob, and cassie will all receive a signal message reading "hello world!" from +1-666...

GIVEN the above

• WHEN bob sends any message to +1-666...
• THEN nobody sees it