Update deps.sh for Python 3 jefferson

Jefferson has moved to Python 3. This requires changes to `deps.sh`

deps.sh

@@ -85,9 +85,9 @@ function install_sasquatch
 
 function install_jefferson
 {
-    install_pip_package "cstruct==1.0"
+    install_pip_package "-r requirements.txt"
     git clone https://github.com/sviehb/jefferson
-    (cd jefferson && $SUDO python2 setup.py install)
+    (cd jefferson && $SUDO pip3 install -r requirements.txt && $SUDO python3 setup.py install)
     $SUDO rm -rf jefferson
 }