paper-chip-input allows chips to be removed when readonly

[dsyrstad]

If paper-chip-input is marked with the readonly attribute, the paper-chips are still removable (paper-chip always has the removable attribute set). Probably an easy fix to say: removable="[[!readonly]]".

paper-chip/paper-chip-input.html

Line 182 in d7cb14f

<paper-chip value="[[value]]" on-remove="_removeChip" removable single-line>