Test xml.file is not generated

Hi, I am working on a Mac and I am building a plain Swift project (no Xcode project).
I've done all steps in the Readme (without the steps for Xcode, as it is no Xcode project) but no test.xml file is getting generated. What am I doing wrong or where can I find the generated junit xml-file?

I am doing the following:

```
swift build
Fetching https://github.com/alexaubry/HTMLString.git
Fetching https://github.com/allegro/swift-junit.git
Cloning https://github.com/alexaubry/HTMLString.git
Resolving https://github.com/alexaubry/HTMLString.git at 5.0.0
Cloning https://github.com/allegro/swift-junit.git
Resolving https://github.com/allegro/swift-junit.git at 2.0.0

swift test
...
Test Suite 'All tests' passed at 2020-11-02 14:52:15.834.
Executed 2 tests, with 0 failures (0 unexpected) in 0.086 (0.086) seconds
```

This is my Package.swift:

```
// swift-tools-version:5.2
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
name: "swiftExercise",
dependencies: [
.package(name: "SwiftTestReporter", url: "https://github.com/allegro/swift-junit.git", from: "2.0.0"),
],
targets: [
.target(name: "swiftExerciseLib"),
.target(name: "swiftExerciseApp", dependencies: ["swiftExerciseLib"]),
.testTarget(name: "swiftExerciseTests", dependencies: ["swiftExerciseLib", "SwiftTestReporter"]),
]
)

```

My Swift version: Apple Swift version 5.2.2 (swiftlang-1103.0.32.6 clang-1103.0.32.51)