* jp-kernel: upgraded to version 1
  - Started implementation of Jupyter Messaging Protocol v5.1.
  - Provided `$$.clear({wait}) to send a `clear_output` request.
  - Provided `$$.display({id})` to send `display_data` and
    `update_display_data` messages.
  - Provided `$$.input(options, {callback})` to send a
   `input_request` and handle `input_reply` messages.

* Setup Travis

* lint: replaced jshint with eslint@2