v1.5.0

• Added additional checks for abridged club data to avoid undefined index/property errors https://wordpress.org/support/topic/club-activities-bugs-strava/
• Added composer with PSR-0 autoloader (will switch to PSR-4 once WP's PHP 5.2 requirement goes away).
• Moved files into appropriate place to support autoloader.
• Added WordPress-Extra coding standards rule definition to project