Fix enum version to prevent it from using older versions

[besirkurtulmus]

As seen here: https://github.com/algorithmiaio/algorithmia-python/issues/17 users can have the following error when they use the client:

Traceback (most recent call last): ....... import re File "....py", line 142, in <module> class 

RegexFlag(enum.IntFlag): AttributeError: module 'enum' has no attribute 'IntFlag'

This happens when the user has a conflicting version on enum installed. enum.IntFlag was added in version 3.6 of enum.

This PR makes changes to the setup.py file to only install enum34 on versions older than Python3.4. I've also fixed the enum34 version to the latest version.