feat(Bot): add loadWebHook function to load all webhooks

works similarly to plugin loading atm
feat(Bot): allow plugins to access the regex match
feat(OutgoingMessage): functions to get and set to and from
docs(config.example.js): add webhooks key
feat(Bot,Brain): Allow incoming webhooks

Breaking:
plugins are now `sublevel`ed inside of a `plugins` key.
#6
feat(webhooks/echo): add echo webhook

simply echoes the webhook url
fix(Bot): Error when logging when no request body

needed to fix for webhook suppport (#6)
test($Bot): handleWebHook basic usage
docs(README): Webhooks section

#6
docs(README.md): add features section