Python 3 compatibility

[jlafon]

I've done some hacking and made dynamic-dynamodb work with botocore and PynamoDB, a first step toward Python 3 compatibility. Although my experimental port works, there are a few issues:

• Testing There don't appear to be any tests for the parts of dynamic-dynamodb that interact with boto. As a consequence, the only way I can test my changes is to actually run the code. The lack of a test suite makes me hesitant to finish this because I have no way of knowing if I've made a breaking change. Since I don't want to pay for tables in DynamoDB just for testing, I'd like to use my port with dynamodb-local. See the next bullet.
• Support for dynamodb-local Support for dynamodb-local would be valuable for testing and development. It would require extending dynamic-dynamodb's configuration to support custom endpoints (such as http://localhost). I had hoped to implement this without any API changes, but I don't see an alternative.
• Other Amazon services I see that boto is being used for other Amazon services, and those uses would have to be converted to botocore. As a library, botocore is very low level, so I don't expect the conversion from boto to botocore for other services to be trivial.

Before I proceed, I'd like to know what you think about the issues above. I'd be happy to send a PR, but since this would be quite a bit of work I want to make sure that you would accept my changes.

Thanks!

[sebdah]

Thanks for looking at this @jlafon! I have been really interested in getting dynamic-dynamodb and a bunch of other things I write ported to Python 3, but the main problem has always been boto. You're third bullet is the only reason that I have not converted dynamic-dynamodb.

I would also like to get testing in place and my idea has, just like you suggest, been to implement that using dynamodb-local. Currently I have too little time to spend on that, but I hope to get some help with that from others with that (someone said to be interested in looking at that in a month or two).

I'd be happy to merge, but I that the obstacles are a bit to big until we have a broader support for Python 3 in boto (or some other library) and more testing in place..

Cheers!