Remove extract_dir from git-lfs
Remove extract_dir from git-lfs

Fixes:
````
Extracting... Error moving directory:
 -------------------------------------------------------------------------------    ROBOCOPY     ::     Robust File Copy for Windows
-------------------------------------------------------------------------------    Started : Thu Feb 16 16:22:35 2017     Source :
C:\Users\ross\scoop\apps\git-lfs\1.5.6\_scoop_extract\git-lfs-windows-amd64-1.5.6\      Dest : C:\Users\ross\scoop\apps\git-lfs\1.5.6\      Files : *.*                Options : *.* /S /E

/COPY:DAT /MOVE /R:1000000 /W:30   ------------------------------------------------------------------------------  2017/02/16 16:22:35 ERROR 2 (0x00000002) Accessing Source Directory
C:\Users\ross\scoop\apps\git-lfs\1.5.6\_scoop_extract\git-lfs-windows-amd64-1.5.6\ The system cannot find the file specified.
At C:\Users\ross\scoop\apps\scoop\current\lib\core.ps1:131 char:9
+         throw "Error moving directory: `n$out"
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (Error moving di...ile specified. :String) [], RuntimeException
    + FullyQualifiedErrorId : Error moving directory:
     -------------------------------------------------------------------------------    ROBOCOPY     ::     Robust File Copy for Windows                               ------------------
   -------------------------------------------------------------    Started : Thu Feb 16 16:22:35 2017     Source : C:\Users\ross\scoop\apps\git-lfs\1.5.6\_scoop_extract\git-lfs-window
  s-amd64-1.5.6\      Dest : C:\Users\ross\scoop\apps\git-lfs\1.5.6\      Files : *.*          Options : *.* /S /E /COPY:DAT /MOVE /R:1000000 /W:30   ----------------------------------

 --------------------------------------------  2017/02/16 16:22:35 ERROR 2 (0x00000002) Accessing Source Directory C:\Users\ross\scoop\apps\git-lfs\1.5.6\_scoop_extract\git-lfs-windo
ws-amd64-1.5.6\ The system cannot find the file specified.
````
rasa/scoop,nueko/scoop,nikolasd/scoop,reelsense/scoop,Cyianor/scoop,rodericktech/scoop,coonce/scoop,bpollack/scoop,toxeus/scoop,vinaynambiar/lukesampson-,Congee/scoop,yunspace/scoop,lukesampson/scoop,vidarkongsli/scoop,berwyn/scoop,r15ch13/scoop,kodybrown/scoop