cron description improved

- also trailing newline removed
unused file removed
prefering unix line ending character

seems first developed on windows
all extra line trailing <CR> characters removed
consistend quote character usage

- prefer `"` more than `'` in yaml
tiny refactoring in mongolbank.py

- used 4 spaces in indent, instead of tab
tiny refactoring in main.py

- unused imports removed
- lot of static changes