devel/ruby-test-unit: update to 3.3.4

Update ruby-test-unit to 3.3.4.

## 3.3.4 - 2019-09-30 {#version-3-3-4}

### Improvements

  * Converted markup format to Markdown from RDoc.
    [GitHub#164][Patch by OGAWA KenIchi]

  * test: Stopped to depend on `Time#inspect` format.
    [GitHub#165][Reported by Benoit Daloze]

### Thanks

  * OGAWA KenIchi

  * Benoit Daloze

## 3.3.3 - 2019-05-10 {#version-3-3-3}

### Fixed

  * Fixed a bug that priority mode with test case name that uses
    special characters such as `?` can't be used on Windows.

(taca)