Fix "Invalid Status Code: [object Object]" message

Being unable to parse the response object (it being circular),
and judging from the rest of the message, pick up statusCode
of response object instead.
Update version of riak pbc in package.json
Use .end() and not .disconnect()
Enable travis
Disable node 0.8
Update dependencies
Update usage of riakpbc
Update tests
Merge remote-tracking branch 'alde/invalid_status_code_message' into update-riak-pbc
Debug on Travis
Merge pull request #226 from mostlyserious/update-riak-pbc

Updating Riak-JS and dependencies