Make `CLI` behavior and output to match latest conventions

This updates the `CLI` behavior and output to match our latest
conventions. This includes a few small changes:

* Only output the version number when using the `--version` flag.
  This makes it easier to parse the actual version number and
  doesn't hurt the readability.
* Fix a minor behavior problem with only passing a config file.
  When this was done, the CLI would use the config file as the
  command instead of assuming `run` for the command and using
  the config file. This corrects that behavior.
* Update the output of the help message. This is a better
  explanation for using the command and matches our latest
  conventions.
* Code/Test cleanups and updates to match our latest conventions.
Merge pull request #145 from redding/jcr-cli-cleanups

Make `CLI` behavior and output to match latest conventions
Fix a bug when inspecting a service handler

This fixes a bug when inspecting a service handler. The previous
implementation called a private method with `self.` which caused
it to throw an error. This didn't fail in the tests because they
were previously making the request, params and logger public.
This changes the tests to not rely on making these public so the
inspect method would fail. This was a particularly annoying
issue when testing handlers because they are inspected by
default.
Merge pull request #146 from redding/jcr-service-handler-inspect-bug

Fix a bug when inspecting a service handler