readFile needs a newline

This isn't strictly right yet (there should be no newline on the last
lie if there was no newline in the input file) but it puts the behaviour
back to what it was before fGetLine was changed to discard it.

This needs revisiting...

libs/base/System/File.idr

@@ -147,7 +147,7 @@ readFile file
                 else
                   do Right str <- fGetLine h
                         | Left err => pure (Left err)
-                     read (str :: acc) h
+                     read ((str ++ "\n") :: acc) h
 
 ||| Write a string to a file
 export