cpanfile: add Test2-Harness and JUnit formatter

These allow testing with yath, which is a big step up from prove.

The JUnit formatter means that a JUnit XML file can be spit out from
tests, which can be processed by (for example)
mikepenz/action-junit-report, to get nicely formatted test reports in
the GitHub UI.

Author: rjbs

cpanfile

@@ -52,9 +52,14 @@ if ( "$]" >= 5.010 ) {
     requires 'Devel::Cover::Report::Codecov';
     requires 'Devel::Cover::Report::Coveralls';
     requires 'Minilla';
+    requires 'Test2::Harness';
     requires 'Test::Vars';
 }
 
+if ( "$]" >= 5.010001 ) {
+    requires 'Test2::Harness::Renderer::JUnit';
+}
+
 if ( "$]" >= 5.012 ) {
     requires 'Code::TidyAll::Plugin::SortLines::Naturally';
     requires 'Code::TidyAll::Plugin::Test::Vars';