Merge pull request #373 from ajm113/bugfix-has-icon-group-fix

Fixed icons disappearing on group classes on focus.

src/_forms.scss

@@ -165,6 +165,7 @@ textarea.form-input {
     top: 50%;
     transform: translateY(-50%);
     width: $control-icon-size;
+    z-index: $zindex-0 + 1;
   }
 }