todoman: Homebrew test block fails with 3.1.0

See https://github.com/Homebrew/homebrew-core/pull/12581 https://bot.brew.sh/job/Homebrew Core Pull Requests/63/version=sierra/console

  test do
    ENV["LC_ALL"] = "en_US.UTF-8"
    (testpath/".config/todoman/todoman.conf").write <<-EOS.undent
      [main]
      path = #{testpath}/.calendar/*
      date_format = %Y-%m-%d
      default_list = Personal
    EOS
    (testpath/".calendar/Personal").mkpath
    system "#{bin}/todo", "new", "newtodo"
    assert_match "newtodo", shell_output("#{bin}/todo list")
  end

fails with the error

iMac-TMP:homebrew-core joe$ brew test todoman -vd
/usr/local/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaLoader): loading /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/todoman.rb
Testing todoman
==> Using the sandbox
/usr/bin/sandbox-exec -f /tmp/homebrew20170417-58560-74t3z5.sb /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby -W0 -I /usr/local/Homebrew/Library/Homebrew -- /usr/local/Homebrew/Library/Homebrew/test.rb /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/todoman.rb -vd
/usr/local/Homebrew/Library/Homebrew/test.rb (Formulary::FromPathLoader): loading /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/todoman.rb
==> /usr/local/Cellar/todoman/3.1.0/bin/todo new newtodo
Traceback (most recent call last):
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/configobj.py", line 1942, in _handle_configspec
    _inspec=True)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/configobj.py", line 1229, in __init__
    self._load(infile, configspec)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/configobj.py", line 1240, in _load
    raise IOError('Config file not found: "%s".' % self.filename)
OSError: Config file not found: "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/todoman/confspec.ini".

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/Cellar/todoman/3.1.0/bin/todo", line 11, in <module>
    load_entry_point('todoman==3.1.0', 'console_scripts', 'todo')()
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click/core.py", line 1063, in invoke
    Command.invoke(self, ctx)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click/core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click/core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click_log/core.py", line 94, in wrapper
    return f(*args, **kwargs)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/todoman/cli.py", line 31, in wrapper
    return f(*a, **kw)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/todoman/cli.py", line 213, in cli
    ctx.config = load_config()
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/todoman/configuration.py", line 81, in load_config
    config = ConfigObj(path, configspec=specpath, file_error=True)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/configobj.py", line 1229, in __init__
    self._load(infile, configspec)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/configobj.py", line 1325, in _load
    self._handle_configspec(configspec)
  File "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/configobj.py", line 1948, in _handle_configspec
    raise IOError('Reading configspec failed: %s' % e)
OSError: Reading configspec failed: Config file not found: "/usr/local/Cellar/todoman/3.1.0/libexec/lib/python3.6/site-packages/todoman/confspec.ini".
/usr/local/Homebrew/Library/Homebrew/debrew.rb:11:in `raise'
BuildError: Failed executing: /usr/local/Cellar/todoman/3.1.0/bin/todo new newtodo
1. raise
2. ignore
3. backtrace
4. irb
5. shell

@hobarrera Any idea what the problem might be?