add dtkTest header file (no .h extension extension)
add dtkTest header file (no .h extension extension)

rdebroiz/dtk,NicolasSchnitzler/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,d-tk/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk,d-tk/dtk,rdebroiz/dtk,NicolasSchnitzler/dtk