Fixed reliability problem with absolute paths.

sweep.bash

@@ -60,7 +60,7 @@ if [ "${#DESIGN_FILES[@]}" -lt 1 ]; then
     echo "Error: No design files (DESIGN_FILES) provided." && exit -1
 fi
 for file in "${DESIGN_FILES[@]}"; do
-    if [ -f "$file" ]; then
+    if ! [ -f "$file" ]; then
         echo "Error: Could not locate design file '$file'." && exit -1
     fi
 done