changed all existence checks to use `in` - fixes 732
add ellipsis test
Added "background-clip: text" test
Updated "background-clip: text" test to use testAllProps()
Merge pull request #925 from ausi/test-backgroundcliptext

Added "background-clip: text" test
Merge pull request #1003 from patrickkettner/ellipsis

add ellipsis test - fixes #188
Merge pull request #989 from patrickkettner/in_is_in

changed all existence checks to use `in` - fixes 732