Fix specs.

Specifically:

- Do not run PSC authority specs outside of JRuby.  (The PSC authority
  specs must be run on JRuby or some compatible implementation because
  they expect the Java module to be present.)
- Fix paths in the spec helper.  (I'm not sure how the spec suite was
  ever runnable with this error.)
- Declare ci_reporter as a development dependency.
Make Core::Authority accept an options hash.

This changes the API, but IMO it's a change for the better.  It is far
more conventional to pass in an options hash than an
Aker::Configuration.
Add an example to demonstrate that the Ops URI is configurable.

This commit also makes Core::Authority#staff_portal_uri public for
testing purposes.
Direct accessors for Core::Authority's Staff Portal configuration.

Applications like NCS Navigator Pancakes read this data from sources
that aren't navigator.ini (because it's more convenient to do that in
e.g. testing).  It should be possible to use Core::Authority in such
situations.
Merge pull request #6 from NUBIC/configurable-sp-url

Make Core::Authority#staff_portal_uri configurable