Add support for prior API versions

Currently only 2.3 is supported. Would be great to have the ability to specify the API version when setting the server URL.

[graysonarts]

Thanks for the issue. You can do the following to change versions:

# assume you have created a server object but have not signed in yet
server.version = 2.4  # Or whatever

This allows you to set the version, but it doesn't do any checking to makes sure it's a valid version, yet.

We are planning to add version checking to all of the methods so if you are trying to use a version where the particular feature isn't supported, we throw an exception.

Perfect. Thanks!

[LGraber]

Note, also, that you can change the version in between calls. You can sign in with version 2.3 and call server.workbooks.get on 2.4. I have no idea why you would but we made sure it would work.

[reevery]

I'm successfully running some queries with 2.2 as well. I've found a couple which don't work aside from the ones without endpoints.
server.workbooks.publish gives 400011 errors with 2.2.

[graysonarts]

@reevery Are you still running into problems? If so, could you give us more information? A copy of the script and workbook would help, as well as server version, and a fiddler trace of the publishing call. in v0.4.x we now throw errors is your Server object is trying to use a version that is too old for the functionality.

[graysonarts]

I just fixed a bug related to namespaces that also caused problems with older versions of the server. 0.5 will have this fix in it. Please let me know (once 0.5 releases) if you are still running into this issue.