Hook command scaffolding

[morgan-wowk]

Hook command scaffolding

Changes:

• Creates hook command - This will be responsible for hooking cvm onto the current shell so that it can executes commands on directory change.
• Creates abstract shell
• Creates ShellZsh with hook to call scan command
• Creates ShellBash with hook to call scan command
• Creates shell_service get_shell_by_name helper function

Feature updates:

• cvm now detects when you enter a folder with a cvm config
• cvm will read the config, install the composer version if valid and update the PATH

Known issues:

• PATH will get updated with multiple / duplicate versions
• Versions do not yet get removed from the PATH

Use as eval "$(cvm hook zsh)"