support outputting test results to JUnit XML and JSON format

[jaypipes]

Support outputting in JUnit XML format and its JSON-ified equivalent.

JUnit example from IBM docs:

<?xml version="1.0" encoding="UTF-8" ?> 
   <testsuites id="20140612_170519" name="New_configuration (14/06/12 17:05:19)" tests="225" failures="1262" time="0.001">
      <testsuite id="codereview.cobol.analysisProvider" name="COBOL Code Review" tests="45" failures="17" time="0.001">
         <testcase id="codereview.cobol.rules.ProgramIdRule" name="Use a program name that matches the source file name" time="0.001">
            <failure message="PROGRAM.cbl:2 Use a program name that matches the source file name" type="WARNING">
WARNING: Use a program name that matches the source file name
Category: COBOL Code Review – Naming Conventions
File: /project/PROGRAM.cbl
Line: 2
      </failure>
    </testcase>
  </testsuite>
</testsuites>