added properties to uiViewController
added TopicTableDataSource
refractored topictableviewdatasourcestest
renamed topictableviewdatasourcestest to topicTableViewDataSourceTests
added a test to make sure one table row was added since there was only one topic
added test for two topics
added test to ensure only one section returned
added two tests to make sure data source doesnt create more sections or rows than needed
added test to make sure data source indicates which topic was selected