tests: Build all available image types during integration test

comparing to lorax-composer test suite only ext4-filesystem and
partitioned-disk are built without asserting anything other than
the build succeeds. For the rest of the images we usually try to
boot them and verify the resulting VM works somehow.

cmd/osbuild-tests/main.go

@@ -60,7 +60,14 @@ func main() {
 	runComposerCLI(false, "status", "show")
 
 	// Full integration tests
+	testCompose("ami")
+	testCompose("ext4-filesystem")
+	testCompose("openstack")
+	testCompose("partitioned-disk")
 	testCompose("qcow2")
+	testCompose("tar")
+	testCompose("vhd")
+	testCompose("vmdk")
 }
 
 func testCompose(outputType string) {