Correct read_word test

[gyu-don]

In assignments/1_io_library/stud/test.py, test cases of read_word uses str.split().
Due to this, whitespace in test cases are ignored. Therefore, some cases are commented out.

         'read_word'            
         : ['-1'], # , '-1234asdasd5234121', '', '   ', '\t   ', 'hey ya ye ya', 'hello world' ],

However, calling str.split() is not necessary for read_word test.