Python 3 / Tensorflow 1.12.0 Compatibility

[berkgercek]

This is a set of changes to the base code of PredNet which allows it to run successfully on python 3.6, using the latest Tensorflow (TF 1.12.0) and Keras (2.2.4) installations available. The major changes to make prednet work in python 3 are:

• the obvious changes to print statements

• changes to the source of imread and imresize in process_kitti.py (the versions in scipy.misc found in the original code are no longer available in that package in python 3)

• the addition of a __getitem__ method to the SequenceGenerator class in data_utils.py due to changes in python 3 regarding the implementation of the next method

• Changes to the way _index_generator in SequenceGenerator is used to reflect changes to Keras' Iterator class which it inherits that method from

EDIT// As a note this has been tested on CUDA 9.0 (which I believe is the latest version supported by tensorflow) and CUDNN 7.4.1.5

Hope this will be as useful to others as it will be to me!

[bill-lotter]

Thanks so much for this and sorry it took me awhile to test!