Erased /usr/bin/env on accident. How can I restore it? I accidentally deleted /usr/bin/env and it causing issues when I want to run 

brew install python


I am getting the following error:

brew install python3
/usr/local/bin/brew: line 91: /usr/bin/env: No such file or directory
/usr/local/bin/brew: line 91: exec: /usr/bin/env: cannot execute: No such file or directory


I know this was a mistake, can anyone help me get this file back?
Running brew install coreutils should install the GNU version of env.