Don't use custom built-in elements because they are not supported in webkit

src/modules/record_sheet.js

@@ -82,7 +82,7 @@ function createRecord(unit) {
   const { dataset: { allegiance, number, squad }} = unit,
     primaryWeapon = unit.querySelector('.primary-weapon'),
     pw = primaryWeapon.getAttributeNS(null, 'href').split('#').pop() || 'rifle',
-    div = document.createElement('div', { is: 'soldier-record-block' }),
+    div = document.createElement('soldier-record-block'),
     spans = Array(6).fill('span').map(t => document.createElement(t)),
     [tn, sn, pwt, pwd, pwrs, pwrl] = spans;