User Story - Slack Bot (#21)

[avincent6]

Expected Behavior

As a user, I would like to use a Slack bot that uses simplif.ai (User Story #21).

Tasks

• Hook into Slack API (Sawyer)
• Create backend logic for slack bot to
  communicate with summarizing API (Sawyer)
• Create the slack bot in its own app.js that
  will house the frontend logic of the bot (Sawyer)
• Write tests for slack bot to ensure proper
  functionality (Sawyer)