Fix about_triangle_project koan

* Easier than I thought it would be.

* When it passed the first time I coded it up
  in IRB to make sure it was right.

* Had to add "./" to require statement.

[#54145671]
Merge pull request #15 from bayendor/54145671_about_triangle_project_master

Fix about_triangle_project koan

[Delivers #54145671]