There is error in README.md

[aimuch]

I try to train my dataset, I find there is error in FPN_Tensorflow_Rotation README.md

(3) Add data_name to $PATH_ROOT/data/io/read_tfrecord.py 

The correct file name is :

(3) Add data_name to $PATH_ROOT/data/io/read_tfrecord_multi_gpu.py 

[yangxue0827]

thx @aimuch