To test:
User A requests friendship of User B
User A has copy of request in their outbox

User B has request in their inbox
User B accepts the request

User A has copy of acceptance in their inbox

Before patch:
User B has no copy of acceptance in outbox

After patch:
User B has copy of acceptance in outbox

- Also fixed if user rejects the request as well

Change-Id: If9097fdbfe26362e949acdfbb93e3fb369d94a6c
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>