Move Linux to 5.9.3

.travis.yml

@@ -73,9 +73,9 @@ before_install:
 install:
   # linux dependencies: qt
   - if [ "${SPEC}" = "linux-g++-64" ]; then
-        wget --quiet https://s3-us-west-2.amazonaws.com/qgroundcontrol/dependencies/Qt5.9.1-linux-min.tar.bz2 &&
-        tar jxf Qt5.9.1-linux-min.tar.bz2 -C /tmp &&
-        export PATH=/tmp/Qt5.9-linux/5.9.1/gcc_64/bin:$PATH &&
+        wget --quiet https://s3-us-west-2.amazonaws.com/qgroundcontrol/dependencies/Qt5.9.3-gcc_64-min.tar.bz2 &&
+        tar jxf Qt5.9.3-gcc_64-min.tar.bz2 -C /tmp &&
+        export PATH=/tmp/Qt5.9-gcc_64/5.9.3/gcc_64/bin:$PATH &&
         export DISPLAY=:99.0 &&
         sh -e /etc/init.d/xvfb start
         ;