Disable pythran testing in Py3.8 for now since it fails.

.travis.yml

@@ -150,7 +150,7 @@ script:
     else
       STYLE_ARGS=--no-code-style;
       if $PYTHON_DBG -V >&2; then CFLAGS="-O0 -ggdb" $PYTHON_DBG runtests.py -vv --no-code-style Debugger --backends=$BACKEND; fi;
-      if [ -z "${BACKEND##*cpp*}" -a -n "${TRAVIS_PYTHON_VERSION##2.6*}" ]; then pip install pythran; fi;
+      if [ -z "${BACKEND##*cpp*}" -a -n "${TRAVIS_PYTHON_VERSION##2.6*}" -a -n "${TRAVIS_PYTHON_VERSION##3.8*}" ]; then pip install pythran; fi;
       if [ "$BACKEND" != "cpp" -a -n "${TRAVIS_PYTHON_VERSION##2*}" ]; then pip install mypy; fi;
     fi
   - if [ "$COVERAGE" != "1" ]; then CFLAGS="-O2 -ggdb -Wall -Wextra $(python -c 'import sys; print("-fno-strict-aliasing" if sys.version_info[0] == 2 else "")')" python setup.py build_ext -i; fi