Test fixes (#3608)
Test fixes (#3608)

* We mis-named color_test, and that caused it to never get run!

* imagespeed_test is meant for benchmarking only, run by hand.
  We don't make a testsuite test, so don't even build the source
  (which would never be counted for code coverage because it doesn't
  run) during CI.
OpenImageIO/oiio,lgritz/oiio,lgritz/oiio,OpenImageIO/oiio,OpenImageIO/oiio,OpenImageIO/oiio,lgritz/oiio,lgritz/oiio