add "panda" test.
more add test.
add "Nn" test
add "Eva" test
change Exception test to ExpectException rule.
Add InitialWord#of test
Add InitialWord#of test on "Nn".
change OnlyWordPickUpUserTest.
Add Javadoc on InitialWord.
add Javadoc on Judge
Add Javadoc on Main.
Add Javadoc on InitialWord.