'kanso upload' should handle multi-line strings

When uploading data using 'kanso upload', the parsing of the JSON string fails if the string contains a new line.  e.g.:

     mgmarino% cat tmp.json 
    {
      "_id" : "'test'",
      "astring" : "test


     +1"
    }
     mgmarino% kanso upload -f tmp.json http://127.0.0.1:5984/test
    Uploading docs to http://127.0.0.1:5984/test
    Reading tmp.json
    Error: SyntaxError: Unexpected token 
    
        at Object.parse (native)
        at ParseStream.Native (/usr/local/lib/node_modules/kanso/lib/data-   stream/ParseStream.js:78:26)


This can be difficult to input data into JSON that is multi-line (e.g. scripts, etc.) so these multi-line strings should be properly escaped.