Hostname and timestamp properties in generated JUnit XML reports

[acabarbaye]

this is a similar issue to pytest-dev/pytest#5471 which used to be in pytest

The schema of Junit reports (http://windyroad.com.au/dl/Open%20Source/JUnit.xsd) defines some required fields such as timestamp or hostname in testsuite xml element which rendering tools such as Allure rely on.
Current output of go-junit-report is, as follows:

<?xml version="1.0" encoding="UTF-8"?>
<testsuites>
	<testsuite tests="2" failures="2" time="600.111" name="...">
		<properties>
			<property name="go.version" value="go1.14.2"></property>
		</properties>
		<testcase classname="..." name="..." time="0.000">
			<failure message="Failed" type=""></failure>
		</testcase>
		<testcase classname="..." name="..." time="0.000">
...................
		</testcase>
	</testsuite>
</testsuites>

Could such xml attributes be added?