chore(PULL_REQUEST_TEMPLATE): ReSpec are automatic

The checks now happen on TravisCI, so we don't need this checkbox anymore.

Author: Marcos Cáceres

.github/PULL_REQUEST_TEMPLATE.md

@@ -2,11 +2,10 @@ Closes #???
 
 The following tasks have been completed:
 
- * [ ] Confirmed there are no ReSpec/BikeShed errors or warnings.
  * [ ] Modified Web platform tests (link to pull request)
 
 Implementation commitment:
 
  * [ ] WebKit (https://bugs.webkit.org/show_bug.cgi?id=)
  * [ ] Chromium (https://bugs.chromium.org/p/chromium/issues/detail?id=)
- * [ ] Gecko (https://bugzilla.mozilla.org/show_bug.cgi?id=)
+ * [ ] Gecko (https://bugzilla.mozilla.org/show_bug.cgi?id=)