update README.

Author: jramak

README.md

@@ -4,7 +4,7 @@ Code for the paper "On Anomaly Detection for Walmart's Online Pricing System."
 
 ## Packages
 
-In order to run models, these python packages are needed:
+This code works on Python 2.7. In order to run models, these python packages are needed:
 
 - pyod
 - scikit-learn
@@ -18,6 +18,8 @@ We can run the various models by providing the model name: gaussiannb, iforest,
 ipython train_evaluate_model.py -- --model autoencoder --input-filename input_data.pkl --output-filename autoencoder_output.pkl
 ```
 
+However, the input files are not currently part of the repository, and thus, the above command will not run successfully. We plan to include some sample data files in the future.
+
 ## Contact
 
 If you have questions, feel free to send an email to jramakrishnan@walmartlabs.com.