Icarus Rev B

Forgot to make a post about the Rev B of Icarus (I did this a few months ago). This is primarily about reducing the size of the PCB and fixing some mistakes in the Rev A board.

Changes:

• Fixed USB component selection
• Selected smaller push buttons
• Selected a smaller package for 3.3V regulator
• Created a Icarus shield footprint that can be layout with other boards
• The SWD header is removed and pads we added to the underside of the board
• Added a barometer