Fix typo causing atom-sink to raise ClassCastException

Fixes ClassCastException lamina.core.channel$channel cannot be cast to lamina.core.channel.IChannel  lamina.core.channel/receive-all (channel.clj:253) for all calls to `atom-sink`
Merge pull request #77 from avh4/fix-atom-sink-typo

Fix atom sink typo causing ClassCastException