Update checkboxes (#2124)

Update all checkboxes to latest style

contributes to hyperledger/composer#2032

Author: cazfletch

packages/composer-playground/src/app/identity/issue-identity/issue-identity.component.html

@@ -28,7 +28,7 @@ <h1>Issue New Identity</h1>
 
       <div>
         <input type="checkbox" [(ngModel)]="issuer" id="issuer" name="issuer">
-        <label for="issuer">Allow this ID to issue new IDs (
+        <label class="checkbox-label" for="issuer">Allow this ID to issue new IDs (
           <svg class="standard-icon" aria-hidden="true">
             <use xlink:href="#icon-relationship_16"></use>
           </svg>