Build an HTTP API for image classification and read MRZ

* require to use tensorflow to classify images, that is to find out the image is a passport, or it is an application form, or it is a scanned bank card with a scanned driver license. * require to use twisted or tornado to handle the HTTP requests * require to read MRZ from the passport image, including the MRZ string and passport deatils from the MRZ. The steps for the API: 1. upload an image file 2. API returns JSON result with the file tags, for example, ['passport'] or ['bankcard', 'driver license front'] or ['bank card back', 'driver license back'] etc.. 3. if the image has been identified as a passport, needs to return MRZ information of the passport, including MRZ string and passport details from the MRZ.