Build projects dir instead of returning settings value

Build checks if directory exists as well
Extract settings to re-usable variable in webhooks
Make logger more robust
Introduce Slack logger
Notify slack when a push event is received

Only notify when it is for the tracked branch
Notify when a command is started (git/commands)
Notify slack when a command has ended (success/failed)
Disable slack if no token is provided
Merge branch 'feature/slack' into develop
Bump version
Merge branch 'release/0.4.0' into develop