TEST: use platform newline in test to allow test to pass on Windows

Unit test used "\n" in expected result, but on Windows the expected output is "\r\n". This fix makes the following test failure go away.

Failed tests:
  MainTest.testReportJunit:198->assertStdoutContains:52
Expected: a string containing "D:\sources\OSS\jslint4java\jslint4java\target\test-classes\com\googlecode\jslint4java\bad.js:1:1:'alert' was used before it was defined.\n"
     but: was "<testsuites>
<testsuite failures='1' time='0.001' skipped='0' errors='1' tests='1' name='D:\sources\OSS\jslint4java\jslint4java\target\test-classes\com\googlecode\jslint4java\bad.js'><testcase time='0.001' classname='com.googlecode.jslint4java' name='D:\sources\OSS\jslint4java\jslint4java\target\test-classes\com\googlecode\jslint4java\bad.js'><failure message='Found 2 problems' type='java.lang.AssertionError'>D:\sources\OSS\jslint4java\jslint4java\target\test-classes\com\googlecode\jslint
4java\bad.js:1:1:'alert' was used before it was defined.
D:\sources\OSS\jslint4java\jslint4java\target\test-classes\com\googlecode\jslint4java\bad.js:1:10:Expected ';' and instead saw '(end)'.
</failure></testcase></testsuite>
</testsuites>"