csv-fix: update sha1 and add test

``csv-fix`` 1.3 fails to install due to a SHA1 mismatch:

    $ brew install csv-fix
    ==> Downloading https://bitbucket.org/neilb/csvfix/get/version-1.3.zip
    ######################################################################## 100.0%
    Error: SHA1 mismatch
    Expected: 9d8c4c38abf4be722eb6e3fc967fd2eeb3bd2299
    Actual: 2bca2d461434e7bd799e6c886d8eda769e7d3937
    Archive: /Library/Caches/Homebrew/csv-fix-1.3.zip

This patch updates the hash and adds a test.