lfw experiment: Add argument for the pairs.txt location.
lfw experiment: Add argument for the pairs.txt location.

francisleunggie/openface,nhzandi/openface,sahilshah/openface,Alexx-G/openface,francisleunggie/openface,xinfang/face-recognize,nmabhi/Webface,sumsuddinshojib/openface,sahilshah/openface,nhzandi/openface,sahilshah/openface,cmusatyalab/openface,nmabhi/Webface,sahilshah/openface,Alexx-G/openface,cmusatyalab/openface,francisleunggie/openface,xinfang/face-recognize,Alexx-G/openface,cmusatyalab/openface,nmabhi/Webface,Alexx-G/openface,xinfang/face-recognize,sumsuddinshojib/openface,sumsuddinshojib/openface,nhzandi/openface,nmabhi/Webface,sumsuddinshojib/openface