ccm json - Couldn't change permissions to use sstable2json

Getting this error while trying to see the json output of a sstable.

`ccm node1 json -k test -c test "C:\Users\user1\Desktop\testjson.txt"`
> running
> WARN: Couldn't change permissions to use sstable2json.
> WARN: If it didn't work, you will have to do so manually.
> ['C:\\Users\\user1\\.ccm\\c2\\node1\\data0\\test\\test-71ff922070dc11e7864b5ff09c5396dc\\mb-1-big-Data.db']
> -- mb-1-big-Data.db -----
> Traceback (most recent call last):
> File "E:\Studies\Cassandra\ccm\ccm-master\ccm.py", line 74, in
> cmd.run()
> File "E:\Studies\Cassandra\ccm\ccm-master\ccmlib\cmds\node_cmds.py", line 487, in run
> enumerate_keys=self.options.enumerate_keys)
> File "E:\Studies\Cassandra\ccm\ccm-master\ccmlib\node.py", line 885, in run_sstable2json
> subprocess.call(args, env=env, stdout=out_file)
> File "C:\Program Files\Python27\lib\subprocess.py", line 522, in call
> return Popen(*popenargs, **kwargs).wait()
> File "C:\Program Files\Python27\lib\subprocess.py", line 710, in __init__
> errread, errwrite)
> File "C:\Program Files\Python27\lib\subprocess.py", line 958, in _execute_child
> startupinfo)
> WindowsError: [Error 2] The system cannot find the file specified

Python 2.7, Windows 10

Thanks,
Dinesh

Start with the `json` command in `ccmlib/cmds/node_cmds.py` around line 487, then follow `run_sstable2json` in `ccmlib/node.py` around line 885. Reproduce the command on Windows with Python 2.7 and inspect the reported missing-file failure. Done means the command no longer fails to find the required executable, or reports the missing prerequisite clearly.

Written by the indexing model from the issue text.