Make ua-parser result accessible

[gma2th-jt]

python-user-agents use ua-parser to parse the user agent here

I would like to access the result of ua_parser.user_agent_parser.Parse through python-user-agent lib. It's too bad for me to parse the user agent twice, once with python-user-agent, and once with ua-parser.

What do you think of makingua_dict a property of the UserAgent class? I can summit you a PR.