Update packages.json

Removed redundant keys (some are ignored, some are the same as the default values)

```
======================================================================
FAIL: test_release('Japanize (https://raw.github.com/kik0220/sublimetext_japanize/master/packages.json)', {'details': 'https://github.com/kik0220/sublimetext_japanize', 'date': '2013-08-30 06:00:00', 'platforms': ['*'], 'url': 'https://codeload.github.com/kik0220/sublimetext_japanize/zip/master', 'version': '2013.08.30.06.00.00', 'sublime_text': '>2999'}, False) (__main__.ChannelTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests\test.py", line 74, in wrapper
    return method(self, *params)
  File "tests\test.py", line 220, in _test_release
    'specified' % req)
AssertionError: 'url' unexpectedly found in {'details': 'https://github.com/kik0220/sublimetext_japanize', 'date': '2013-08-30 06:00:00', 'platforms': ['*'], 'url': 'https://codeload.github.com/kik0220/sublimetext_japanize/zip/master', 'version': '2013.08.30.06.00.00', 'sublime_text': '>2999'} : The key "url" is redundant when "details" is specified

======================================================================
FAIL: test_release('Japanize (https://raw.github.com/kik0220/sublimetext_japanize/master/packages.json)', {'details': 'https://github.com/kik0220/sublimetext_japanize/tree/2999', 'date': '2013-08-30 06:00:00', 'platforms': ['*'], 'url': 'https://codeload.github.com/kik0220/sublimetext_japanize/zip/2999', 'version': '2013.08.30.06.00.00', 'sublime_text': '<3000'}, False) (__main__.ChannelTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests\test.py", line 74, in wrapper
    return method(self, *params)
  File "tests\test.py", line 220, in _test_release
    'specified' % req)
AssertionError: 'url' unexpectedly found in {'details': 'https://github.com/kik0220/sublimetext_japanize/tree/2999', 'date': '2013-08-30 06:00:00', 'platforms': ['*'], 'url': 'https://codeload.github.com/kik0220/sublimetext_japanize/zip/2999', 'version': '2013.08.30.06.00.00', 'sublime_text': '<3000'} : The key "url" is redundant when "details" is specified
```