update some settings. add travis

- use `TrieMap` because `scala.collection.mutable.ConcurrentMap` removed
- use `Channel#hashCode`
  - https://github.com/netty/netty/commit/9c1b31d20a2a6f913802f42
  - https://github.com/netty/netty/commit/368156f5d0f3fd59146fe37f874cf77abe307ee7#diff-cfab6ab9111be41b2f39beb8d154e79fL110
- use `unfiltered.netty.Server` instead of `unfiltered.netty.Http`
  - https://github.com/unfiltered/unfiltered/commit/9b7b86b80481fed118c367dc88f22d90c77b1335#diff-25f79a5bd286e58bd0b8cc73cf8af410R34