Add Travis CI setting for auto generating and deploying html

Add Travis CI setting file for auto generating html.

Add deploy_key.enc for auto deploy.
This key is sample key for deploying sample web site.
In this sample, the deployed web site can be checked at
http://hatohol.blue.skydetector.net.

Change unoconv calling option in gen.py for old unoconv supplied by
Ubuntu 12.04 in Travis CI.