fix duplicate suite reports with junit reporter

When the junit reporter is run with the runner, the reports are duplicated. It appears that this is caused by the `/suite/end` topic being published by both `Suite` and `createProxy` (in `publishInSequence`). This appears to only be an issue with the junit reporter, as it appears to count on `/suite/end` to only be called once per suite. This fixes the duplication reported in fixes #275. This change should not affect the junit reporter when executed with client (unit test still passes).