Tmule

What's Changed
* Expand environmental variable during include by pulver22 in https://github.com/marc-hanheide/TMuLE/pull/21

New Contributors
* pulver22 made their first contribution in https://github.com/marc-hanheide/TMuLE/pull/21

**Full Changelog**: https://github.com/marc-hanheide/TMuLE/compare/1.5.8...1.5.9

- https://github.com/marc-hanheide/TMuLE/pull/18
- https://github.com/marc-hanheide/TMuLE/pull/19

All server improvements in this release:

* got rid of dependencies on really deprecated `webnsock`, server now is based directly on `autobahn`/`twisted` libraries. Faster, more robust, leaner...
* most importantly: `twisted` now allows serving the websocket connection through the same port as the webserver. So the entire server app is running on one port, not two, allowing it to be easily deployed behind `ngrok` or similar services, or just on port 8080 for easy deployment.
* The _port_ (option `-p`) allows to configure the port the server is running one.
* The _keepalive_ option (`-k`) now allows to tell the server _not_ to terminate the tmule tasks when existing

some bug fixes to make checks work correctly

This release has some new features:

1. _`wait` per window:_ Rather than one global wait in seconds for auto-launch, you can now configure a wait time for each window (i.e., auto-launching will only commence after waiting specified seconds)
2. _`check` process:_ You can specify a process that is run to check if a window is up. This can be any shell expression. If the exit code is `0`, then the window is deemed running. For instance `rostopic list` is a good check process to ensure that `roscore` has completed its starting up.
3. iterating through all windows for termination is done in reverse order now