Test that setting and getting justify-items works as expected


PASS Test getting justify-items set through CSS. 
PASS Test initial value of justify-items through JS 
PASS Test getting and setting justify-items through JS 
PASS Test 'legacy' value resolution for the root node 
PASS Test bad combinations of justify-items 
PASS Test the value 'initial' 
PASS Test the value 'initial' for grid containers 
PASS Test the value 'initial' for flex containers 
PASS Test the value 'inherit' 
PASS Test the legacy alignment