Putting the better "chat" in "chatbot"

This update replaces the BotLibreService from last update with PandorabotService. I quickly realized after last update that BotLibre bots are pretty awful out of the box - I'd keep both for the sake of choice but this (Pandorabots) actually adds value to the library whereas the other one would just be a dead-end for a developer unaware.

Putting the "chat" in "chatbot"

Added BotLibreService - the library's first actual chat service!

Vision Service tweak

GoogleVisionService now takes in an image encoded as a base64 string. Previously, taking a URL worked only half the time for perfectly valid image links.

Yandex refactoring

Separates language logic from service logic.

The machine learning update

• Add Google Vision service
• Add Yandex Translate service
• Add Watson Personality service
• Improve performance with Google-related commands

ImgurService improvement

Adds an Id field to the model.

Github & Imgur!

Adds GithubService and ImgurService.

OpenWeatherMapService improvement

• Get country code in OWM result
• Automate deployment with Cake

OpenTriviaDbService improvement

• Use accurate names for category enum model.

YouTubeService improvement

• Fetches as many YouTube results as allowed/available by Google (max 50).
  • Previously only fetched up to 5 (API default).
• Clarifies a similar limitiation in the Google service.