Test suite no longer fails in Py3.9, so enable it as a fully supported target in travis.
Test suite no longer fails in Py3.9, so enable it as a fully supported target in travis.

scoder/cython,da-woods/cython,da-woods/cython,scoder/cython,cython/cython,scoder/cython,scoder/cython,cython/cython,da-woods/cython,cython/cython,da-woods/cython,cython/cython