some tweaks to worker/server connecting

- server should now use the ip adress given from worker when worker
connects
- adding a try/except errro if the server can't talk to worker with a
wrong ip
+ fixing the create_random_workers() function (don't think it's used
anyway, but usefull to keep for teting purposes)
Refactoring: removed unused .swp file
Updates to .gitignore file
Refactoring: removed unused .gitignore file