Add api tests
Merge pull request #31 from edmoz/tests-api

Add API tests
Pep8 fixes for python code
Issue #33 - Pass version to client

* modified to pass int64 version to client if version provided.
* If version is not an int64 value, server returns a 403 for updates
* If version is 0 or unspecified, uses a timestamp value.
* Updated test suite.
Added proxyhost pull from Environment

- Allow proxy host to read the $HOST env variable if shard.currentHost
  not set.
Pull the hostname from AWS metadata service

- going a bit further to get the automation right.
Fixes to normalizing config values

- use MzConfig and MzFlag more because DRY