feat(client/deis): add python3 support

Changes:
- use python future for single source
- change octals to new style of `0oXXX`
- add `future==0.14.1` as dependency

Breaking Changes:
- `future==0.14.1` requires python >= 2.6
@Xe from my understanding, `standard_library.install_aliases()` sets `http.cookiejar` to `cookielib` for older packages.