Missing Shebang Lines

[schackartk]

Both of the executable files (i.e. train.py and test.py) do not have a shebang line. While is it not critical
that a shebang line be included, it may be advisable unless there is some reason for not including it.

This could be easily resolved by making the first line of those files:
#!/usr/bin/env python3
With that, users would no longer need to run $ python3 train.py, but could just execute using $ ./train.py. Also, it makes it explicit that the script is to be run with Python 3 instead of Python 2.