Untested modues tracker

[rahulghangas]

This issue tracks untested modules or modules that require further testing

• [x] Peer Discovery (peer/peerdiscovery.go)
  • [x] Full Testing
• [x] Pull based gossiping (peer/sync.go, peer/gossip.go)
  • [ ] Full Testing
• [ ] Filtering (channel/filter.go)
  • [ ] Full Testing
• [x] Channels (channel/channel.go) Broken tests