Fix IGNORE_PROJECT_IDS example (#49)

Author: aetheon

README.md

@@ -52,7 +52,7 @@ jobs:
           BOARD_COLUMN_MERGED: 'Ready to Test'
           BOARD_COLUMN_CLOSED: 'Rejected'
         env:
-          IGNORE_PROJECT_IDS="1,2,3"
+          IGNORE_PROJECT_IDS="1 2 3"
 
 ```