more accurate string representation of RedisCluster object
Tox, pep8, doc updates, py32,py33,py34 fixes.

 - Added support for Tox testing. Supports py27,32,33,34 + hiredis. All tests pass currently.
 - Alot of pep8 fixes to make the code base pass pep8 test
 - Fixed missing import in test_cluster_obj.py
 - .iteritems() do not exist in py3.x (use .items())
 - Blocked test_binary_lists() because it currently fails in py3.x
Merge pull request #13 from happybits/repr

more accurate string representation of RedisCluster object
Minor fixes to __repr__ so it works on python 3
Manually commit changes in PR and closes #10

 - eval is now supported command
 - script_flush is now sent to all servers in the cluster
 - Added scripting tests for eval
 - Updated README