UI update

Added circling percentage circle graph
Added flight date
Layout improvement
Some visual polish including progress spinner while uploading file

First public release

This is the first public release of the Soaring Coach interface. It allows for the following:

• Upload IGC file, this is submitted to Soaring Coach back-end via POST request
• Parse JSON structure returned from back-end and display several pieces of data:
  • Pilot Name
  • Total Track Distance (in meters)
  • Percentage of total flight time spent circling
  • Straight phases in a bar graph, showing distance and what time the straight phase started
  • List of straight phases sorted by distance (longest first), showing distance travelled and what time the straight phase started.