Correction for a mistake in 'last2avg'

[alexlimh]

Dear BERT-Flow authors,

I notice there's a mistake in your code where you attempt to average the last 2 layers of BERT but instead you average the first and last layer of BERT, which has also been pointed out by issue #11.
Specifically, the for-loop at line 172 of your run_siamese.py file starts from 0 instead of 1, which means that you take the average of the first and the last layer.

As BERT-Flow is a very important line of work in STS, which others need to compare with and build upon, please either correct the mistakes in the paper or update the results using the last 2 layers. However, if I'm wrong please correct me.

Best,
Minghan