Changes

tsk 21 Fixes Story test
The test class was moved to the Domain project from the Tests project as
this is only for utility classes used in the tests. The class was
renamed to StoryEntityTest as all test classes must use the Test suffix. 
Method testStoryLengthStory has been removed as it was testing some of
the same functionality as the testStoryDataType method. Further tests
were added to check the content size for each type of genre as each
genre has a different size limit.