updated to Python 3

- updated Python packages to Python 3
- added python3-dateutil

Vagrantfile

@@ -63,15 +63,16 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
       "proj-bin",
       "libreadline-dev",
       "libsqlite3-dev",
-      "libwxgtk3.0-dev",
+      "libwxgtk3.0-gtk3-dev",
       "libxmu-dev",
-      "python",
-      "python-wxgtk3.0",
-      "python-dev",
-      "python-numpy",
-      "python-ply",
-      "python-pil",
-      "python-six",
+      "python3",
+      "python3-wxgtk4.0",
+      "python3-dateutil",
+      "python3-dev",
+      "python3-numpy",
+      "python3-ply",
+      "python3-pil",
+      "python3-six",
       "libnetcdf-dev",
       "netcdf-bin",
       "libblas-dev",