fix: update pubnub package to v7.1.2

Merge pull request #11 from amagimedia/ss_postmaster_v2

postmaster topic v2 changes

postmaster topic v2 changes

notification behaviour changes

fix(pubnub-sub): add pubnub validation to prevent memory leak (#8)

add pubnub config validation to check for empty subscribe key

fix(pubnub-sub): add pubnub validation to prevent memory leak (#8)

add pubnub config validation to check for empty subscribe key

fix(pubnub-sub): add pubnub validation to prevent memory leak (#9)

add pubnub config validation to check for empty subscribe key
#9

fix: update pubnub sub protocol (#7)

update the missing line from judo v2

message format changes

error check ffor ack send