Fix for xcrun: error: invalid active developer path after updating your mac OS to Sierra

If you are geting the following error with Git or any other tools while running it on from your terminal
 xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun. 

 using the following command to fix it
xcode-select --install