Update DummyReader.php

fix typo
PIM-1325 : add update guesser interface to detect the changes
PIM-1325 : add versionable updates guesser
PIM-1325 : add translations updates guesser
PIM-1325 : add contains products update guesser
PIM-1325 : add product value update guesser
PIM-1325 : add attribute group change and attribute option change update
guesser
PIM-1325 : use guessers to replace the internal builder logic
PIM-1325 : update and delete changes are now managed by the same version builder
method
PIM-1325 : add unit test on attribute group guesser
Merge branch 'master' into PIM-1325
PIM-1325 : add versionable update guesser UT
PIM-1325 : add contains product update guesser UT
PIM-1325 : fix translation update guesser and add related unit test
PIM-1325 : add attribute option update guesser UT
Implement attribute option creation from product edit form
Merge branch 'master' into PIM-125
Don't persist product before going to the edit form if associations are missing
PIM-1325 : add product value update guesser UT
Change the add option button UI