Fix Cobertura unit test (#510)

Author: dalbani

reporter/src/main/scala/scoverage/reporter/CoberturaXmlWriter.scala

@@ -26,7 +26,7 @@ class CoberturaXmlWriter(
     val file = new File(outputDir, "cobertura.xml")
     IOUtils.writeToFile(
       file,
-      "<?xml version=\"1.0\"?>\n<!DOCTYPE coverage SYSTEM \"http://cobertura.sourceforge.net/xml/coverage-04.dtd\">\n" +
+      "<?xml version=\"1.0\"?>\n<!DOCTYPE coverage SYSTEM \"https://cobertura.sourceforge.net/xml/coverage-04.dtd\">\n" +
         new PrettyPrinter(120, 4).format(xml(coverage)),
       sourceEncoding
     )

reporter/src/test/resources/scoverage/reporter/cobertura.sample.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<!DOCTYPE coverage SYSTEM "http://cobertura.sourceforge.net/xml/coverage-04.dtd">
+<!DOCTYPE coverage SYSTEM "https://cobertura.sourceforge.net/xml/coverage-04.dtd">
 
 <coverage line-rate="0.9" branch-rate="0.75" version="1.9" timestamp="1187350905008">
     <sources>

reporter/src/test/scala/scoverage/reporter/CoberturaXmlWriterTest.scala

@@ -112,7 +112,7 @@ class CoberturaXmlWriterTest extends FunSuite {
     )
   }
 
-  test("cobertura output validates".ignore) {
+  test("cobertura output validates") {
 
     val dir = tempDir()
 
@@ -298,8 +298,6 @@ class CoberturaXmlWriterTest extends FunSuite {
     writer.write(coverage)
 
     val domFactory = DocumentBuilderFactory.newInstance()
-    // TODO set validating here is no longer working as of 2.13.10. Not fully sure why but I don't use
-    // cobertura, so if someone wants to fix this, please do. I'll move forward with this not to block the release.
     domFactory.setValidating(true)
     val builder = domFactory.newDocumentBuilder()
     builder.setErrorHandler(new ErrorHandler() {