Report generation fails

[coding-bunny]

Hello,

I've included minitest-ci for our projects on CircleCI, but the tests are failing when using minitest with the following error:

[Minitest::CI] Generating test report in JUnit XML format...
/Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:115:in `+': nil can't be coerced into Fixnum (TypeError)
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:115:in `block in generate_results'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:114:in `each'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:114:in `generate_results'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:99:in `block (3 levels) in report'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:98:in `open'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:98:in `block (2 levels) in report'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:97:in `each'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:97:in `block in report'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:96:in `chdir'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-ci-3.4.0/lib/minitest/ci_plugin.rb:96:in `report'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-5.13.0/lib/minitest.rb:864:in `each'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-5.13.0/lib/minitest.rb:864:in `report'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-5.13.0/lib/minitest.rb:146:in `run'
        from /Users/olivar/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/minitest-5.13.0/lib/minitest.rb:68:in `block in autorun'
Coverage report generated for MiniTest to /Users/olivar/RubymineProjects/sales/coverage. 6887 / 7453 LOC (92.41%) covered.

From what I can understand in the test it seems to be missing some kind of timing data resulting in this nil-error.