v3.0.56

• Refactor to support core testlogger
• Compatibility: minimum framework is netstandard1.5 and TestPlatform 15.5.0
• Use test run start and end times for run duration reporting for assembly. See #26
• Escape control characters from the generated xml. See #25
• Token expansion for {assembly} and {framework} in results file. See
  https://github.com/spekt/testlogger/wiki/Logger-Configuration

https://github.com/spekt/xunit.testlogger/blob/master/CHANGELOG.md#v3056---20210131