Fixed #134 -- Added CLI interface

[Bouke]

Great work on this library. However I'd really like using the CLI for a quick validation. So I've produced this little CLI tool for validating a JSON document (file) against a JSON schema (file).

[Julian]

Hey, thanks, sorry I haven't gotten a chance to take a look at this yet, but I do agree it'd be nice to have. I'll try and take a look before the end of the week.

[Julian]

Sorry it took me this look to look :)

Thanks for submitting this – would you be interested in writing a few small tests for the functionality here, if it's something that we're gonna actually support going forward it'd be nice to make sure it continues to work as we evolve it?

Also I see that you're outputting some non-ASCII characters which are UTF-8. Have a feeling that's going to cause issues for windows users who might want to use this.

And the use of entry_points means that we'd actually now depend on setuptools – in the setup.py currently we fall back to distutils (there hasn't actually been a release that has this yet, it's mostly just here to allow running bdist_wheel without needing to modify the setup.py), so we'd either need to remove that or use a regular binary; I think the latter probably is simpler.

[Bouke]

I've updated the PR to include unit tests and removed the UTF-8 character. I spend the better part of my time figuring out py.test (mostly getting it to not capture output when I wanted to see it and failing to capture output when I wanted to). But I think the tests are quite complete as-is.

I don't see how the issue of entry points can be resolved. I haven't updated myself on the whole wheel movement, maybe you could shine a light? http://wheel.readthedocs.org/en/latest/#setuptools-scripts-handling

[Bouke]

I'll investigate why -h or --help doesn't work as expected.

[Bouke]

The failing test doesn't appear to be related to the changes I've made. What are your thoughts on this PR?

[Julian]

Hey, cool.

The failing test is because of the move of the StringIO module in Py3. But this looks pretty good, I can merge one day next week and fix it then along with removing entry_points. And yeah, I don't like py.test either, that's why we don't use it really, it's a bit too obtuse for my liking :/.

Thanks!

[Julian]

Merged, along with some additional functionality -- Thanks for the patch, appreciated!