v0.3.4

Updates:

• Added credits to the main overlay UI.
• Added close button to port UI.
• Reduced pricing on upgrades to make the first upgrade more quickly attainable.
• Made asteroids disappear when entering a port to make sure your ship doesn't get unfairly banged up when coming out of port.
• Added event indicator to display when a new event is available at the port (travel away from the port and return to a make new events appear).
• Modified events so that one will always appear when travelling far enough away. There will still be a chance that its an 'uneventful day' however.