cobertura write fix: added missing required complexity attribute to method

Author: Aaron Pritzlaff

scalac-scoverage-plugin/src/main/scala/scoverage/report/CoberturaXmlWriter.scala

@@ -25,7 +25,8 @@ class CoberturaXmlWriter(sourceDirectories: Seq[File], outputDir: File) extends
     <method name={method.name}
             signature="()V"
             line-rate={format(method.statementCoverage)}
-            branch-rate={format(method.branchCoverage)}>
+            branch-rate={format(method.branchCoverage)}
+            complexity="0">
       <lines>
         {method.statements.map(stmt =>
           <line