Include count of errors occurring outside examples

[Jason Rutherford]

Errors occurring outside examples was added in rspec 3.6 via PR #2351. For example:

...
Finished in 0.00005 seconds (files took 0.17173 seconds to load)
0 examples, 0 failures, 1 error occurred outside of examples

should generate

<?xml version="1.0" encoding="UTF-8"?>
<testsuite name="rspec" tests="0" skipped="0" failures="0" errors="0" errors_outside_of_examples="1" time="0.000041" timestamp="2020-03-10T13:09:51-07:00" hostname="macjrutherford.local">
<properties>
<property name="seed" value="60978"/>
</properties>
</testsuite>

[Samuel Cochran]

Sorry, this is not part of the junit standard output, so will break some consumers of junit output, and cannot be included.