Travis: cope with setuptools upgrade failing

Tools/scripts/install-travis-env.sh

@@ -29,7 +29,9 @@ APT_GET="sudo apt-get -qq --assume-yes"
 
 $APT_GET update
 $APT_GET install $BASE_PKGS $SITL_PKGS $PX4_PKGS $UBUNTU64_PKGS $AVR_PKGS
-pip install --upgrade setuptools
+pip install --upgrade setuptools || {
+    echo "setuptools upgrade failed"
+}
 for pkg in $PYTHON_PKGS; do
     echo "Installing $pkg"
     pip -q install $pkg || echo "FAILED INSTALL OF $pkg"