Return 200 if there are no peers
Add deletes to test
Have null check the correct way round
Update SAS event
Updates after review - null out msg
Merge pull request #92 from Metaswitch/iss91

[Reviewer: Andy] Iss91
Update cpp-common
Merge pull request #93 from Metaswitch/cpp_update

[No reviewer] Update cpp-common
Take latest cpp-common
Update cpp-common
Merge pull request #94 from Metaswitch/update_cppc

[No review required] Update cpp-common
take master cpp-common
Merge pull request #95 from Metaswitch/update_cppc

Take master cpp-common
Change Metaswitch submodule refs to ClearwaterCore