maintainer can raise member limit using `boost` (BACKLOG)

value

• in #372 (closed) we introduce member limits
• we might want to be able to raise member limits on a channel in an emergency situation
• currently we can do that by using a psql session to change the memberLimit field on a channel record, but this requires shutting down signalboost while we do so for the change to persist
• it would be nice if we could do this easily from the cli, so, add command that does so!

behavior

raising limit

GIVEN a channel with phone number +12223334444 and member limit of 500

• WHEN a maintainer enters boost raise-member-limit -p +12223334444 -l 600
• AND WHEN the command succeeds
• THEN the maintainer will receive a message that says Member limit on channel +12223334444 has been set to 600
• AND THEN the channel's member limit will be set to 600

lowering limit

GIVEN a channel with phone number +12223334444 and member limit of 500

• WHEN a maintainer enters boost raise-member-limit -p +12223334444 -l 400
• AND WHEN the command succeeds
• THEN the maintainer will receive a message that says Member limit on channel +12223334444 has been set to 400
• AND THEN the channel's member limit will be set to 400

errors

GIVEN a channel with phone number +12223334444 and member limit of 500

• WHEN a maintainer enters boost raise-member-limit -p +12223334444 -l 600
• AND WHEN the command fails
• THEN the maintainer will receive a message that says ERROR: failed to set member limit on channel +12223334444: <some error string indicating cause of error>
• AND the channel's member limit will remain the same