Added training data for comets

[kousikr26]

No description provided.

[ritwik12]

@kousikr26 Thanks for the training data, are you going to add the code change as well? Please refer to #26 if you need some reference.

[kousikr26]

@ritwik12 Added the code as well please review

[ritwik12]

Please add test data and also update hub/examples/image_retraining/display_info.yml for the same @kousikr26

[kousikr26]

@ritwik12 Added test data, the same problem for comets regarding the display_info.yml

[ritwik12]

@kousikr26 Please remove comet_2.jpg as test data should not be in training data and comet_3.jpgis having text on image which will be a NOISE for classification.
Also please check that test data and training data are not common and all images are real and not computarised. For image_5 .jpg also it will look more like a meteor as it is zoomed image.