Improve deploy script.

- Check that JLinkExe in properly installed
- Verify that the app is installed
- Always report failures in the exit code
- Add vscode settings for Python code formatting using Google style
- Fix issue #42 regarding tockloader version and sticky parameter

.vscode/settings.json

 {
+  "editor.detectIndentation": true,
+  "editor.formatOnPaste": false,
   "editor.formatOnSave": true,
+  "editor.formatOnType": true,
+  "editor.insertSpaces": true,
+  "editor.tabSize": 4,
   "rust-client.channel": "nightly",
   // The toolchain is updated from time to time so let's make sure that RLS is updated too
   "rust-client.updateOnStartup": true,
-  "rust.clippy_preference": "on"
+  "rust.clippy_preference": "on",
+  // Try to make VSCode formating as close as possible to the Google style.
+  "python.formatting.provider": "yapf",
+  "python.formatting.yapfArgs": [
+    "--style=chromium"
+  ],
+  "[python]": {
+    "editor.tabSize": 2
+  },
 }