Added New Commands!

I added a few more commands to wrap up the project. The bot now features:

• Spacenews - Shows upcoming space launches and events
• Calculator - Evaluates simple math such as 5*32 or 75/3
• Flip - Flips a coin
• Roll - Roll any sided dice, simply type in the number-sided dice that you want
• Trivia - Uses an API and clickable buttons to quiz you on your trivia skills.