add basic ruby contrib layer
bind reposition window to z f
enable semantic mode in python contrib by default
Execute correct `clear` and `man` behavior in (e)shell
Move shell config to spacemacs/init-shell
Lazy loading of semantic for python layer
Update Python readme
Remove the `s` prefix for send to REPL bindings in Python
Update ruby layer readme
Update key bindings for running tests according to the conventions

For ruby and python layers
Remove `s` in send to REPL commands for ESS

according to the new convention
Update conventions for send to REPL and test execution