new mock FatSecret server for offline testing

  `npm test` now works -- will travis pass?

  modified:   api/fatsecret/fatsecret.js
    Support reading from env.FATSECRETKEYS and env.FATSECRETURL for
    testing offline, using mock resources.

  modified:   package.json
    Support `npm test` using jasmine-node

  modified:   spec/factory-spec.js
  modified:   spec/fatsecret-spec.js
    Drop in the mock FatSecret server

  new file:   spec/mock/fatSecretServer.js
    New mock FatSecret server for testing

  new file:   spec/mock/utils.js
    Utils module for mock