Add support for detecting nested java archives (#77)

* with sb build app

* test nested jar support

* pin jdk version during parse test (but dont compare version)

integration/fixture_image_language_pkgs_test.go

@@ -3,9 +3,10 @@
 package integration
 
 import (
-	"github.com/anchore/imgbom/internal"
 	"testing"
 
+	"github.com/anchore/imgbom/internal"
+
 	"github.com/anchore/go-testutils"
 	"github.com/anchore/imgbom/imgbom/cataloger"
 	"github.com/anchore/imgbom/imgbom/pkg"
@@ -48,6 +49,7 @@ func TestLanguageImage(t *testing.T) {
 			pkgLanguage: pkg.Java,
 			pkgInfo: map[string]string{
 				"example-java-app-maven": "0.1.0",
+				"example-jenkins-plugin": "1.0-SNAPSHOT", // the jeninks HPI file has a nested JAR of the same name
 			},
 		},
 		{