Alternative converter parameter is case-sensitive #35

The customer complains that the "converter" parameter is case-sensitive and doesn't work as we described in our auto-generated code snippet:

This Python code doesn't switch Converter type - it stays default.

convertapi.api_secret = 'your-api-secret'
convertapi.convert('pdf', {
'File': '/path/to/my_file.csv',
'Converter': 'Printer'
}, from_format = 'csv').save_files('/path/to/dir')

But if I change the "Converter" key "converter" key - it starts working. In GitHub the function uses param["converter"]
https://github.com/ConvertAPI/convertapi-python/blob/master/convertapi/task.py