The response example in README is wrong. Fixed it.

[RyouMon]

Wrong Example

{
    'image_type': 'image/png',
    'image_decode': 'base64',
    'captcha_key': 'de67e7f3-72d9-42d8-9677-ea381610363d',
    'captcha_value': '... image encoded in base64'
}

Fixed Example

{
    'image_type': 'image/png',
    'image_decode': 'base64',
    'captcha_key': 'de67e7f3-72d9-42d8-9677-ea381610363d',
    'captcha_image': '... image encoded in base64'
}