Add Support for Newer Python Versions

Merge pull request #6 from allthingstalk/feature/user-agent

Adds support for User-Agent string

Updates version

Merge branch 'docs-update'

Update versions

Fixes #3

MQTT listener used to match the received asset name with the
internal_id, which didn't work with custom names.

Also adds a section in docs about using custom names.

Python3.4 compatibility for commands

Breaking changes in paho minor release

setup.py classifiers

Bugfix - correct default mqtt point (bump to 0.1.4)

Default mqtt domain was erroneously generated with https:// prefix.