Added Python 2.7 note in readme

README.md

@@ -5,7 +5,7 @@ Code and models accompanying [Deep Predictive Coding Networks for Video Predicti
 The PredNet is a deep recurrent convolutional neural network that is inspired by the neuroscience concept of predictive coding (Rao and Ballard, 1999; Friston, 2005).
 **Check out example prediction videos [here] (https://coxlab.github.io/prednet/).**
 
-The architecture is implemented as a custom layer<sup>1</sup> in [Keras] (http://keras.io/). Tested on Keras 1.0.7 with [theano] (http://deeplearning.net/software/theano/) backend.
+The architecture is implemented as a custom layer<sup>1</sup> in [Keras] (http://keras.io/). Tested on Keras 1.0.7 with [theano] (http://deeplearning.net/software/theano/) backend and Python 2.7.
 See http://keras.io/ for instructions on installing Keras and its list of dependencies.
 For Torch implementation, see [torch-prednet] (https://github.com/e-lab/torch-prednet).
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