Disable mypy usage in tests for Py3.4 since it's no longer supported.

.travis.yml

@@ -147,7 +147,7 @@ script:
       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##*-dev}" ]; then pip install pythran; fi;
-      if [ "$BACKEND" != "cpp" -a -n "${TRAVIS_PYTHON_VERSION##2*}" -a -n "${TRAVIS_PYTHON_VERSION##*-dev}" ]; then pip install mypy; fi;
+      if [ "$BACKEND" != "cpp" -a -n "${TRAVIS_PYTHON_VERSION##2*}" -a -n "${TRAVIS_PYTHON_VERSION##*-dev}" -a -n "${TRAVIS_PYTHON_VERSION##*3.4}" ]; then pip install mypy; fi;
     fi
 # Need to clear the ccache? Try this:
 #  - if [ -n "${BACKEND##*cpp*}" ]; then ccache -C || true; fi