Test: Add unit tests for SteamChatBot.Connect

Add unit tests for the SteamChatBot module. These tests are used to
validate three use cases: when the user provides a username and password
and no sentry file exists, when the user provides a username, password,
and Steam Guard code and no sentry file exists, and when the user
provides a username and password and a sentry file exists.
Test: Add Travis CI support