Relax jest coverage threshold for branches

We can't tell jest to ignore certain branches for coverage purposes
because the hermes parser removes the necessary code comments.

facebook/hermes#1098

Author: necolas

packages/react-strict-dom/tools/jest.config.js

@@ -20,7 +20,7 @@ module.exports = {
   ],
   coverageThreshold: {
     global: {
-      branches: 89,
+      branches: 85,
       functions: 90,
       lines: 95,
       statements: 95