Chore/update to rails 4.1 and ruby 2.1.1/70507552

Cleans up dependencies:

- adds unlisted `timeliness` runtime dependency
- adds `rubocop` as dev dependency
- uses released-to-rubygems version of `netsuite` gem (see 940f225)

(Can't use rubygems version of `netsuite-rest-client` because they deprecated the gem.)