double to single quotes

Author: katyhuff

README.md

@@ -9,7 +9,7 @@ Fuel Cycles group.
 It should be sufficient to do the following:
 
 Clone the repo:
-`git clone [email protected]:arfc/arfc.github.io"
+`git clone [email protected]:arfc/arfc.github.io`
 
 Make your way to the top level of the source branch
 `cd arfc.github.io && git checkout source`