Add email module

After detecting a failure in the feedback, the system should send an email to notify that the issue has been detected. Format:

Recipient	caosnhp@gmail.com
Subject	[CRITICAL] + [LOCATION] + [MONKEY_ID (optional)]
Body	[Some standard message]

Message:

• Pellet dispenser located at + <monkey_id> has failed to deliver. Please go and check it manually.
• The system will shut down (This will require another module/issue)