1.5.0

• [feature] stop append /# before id when no namespace (#2509)
• [feature] Add a 'disconnecting' event to access to socket.rooms upon disconnection (#2332)
• [fix] Fix query string management (#2422)
• [fix] add quote to exec paths, prevent error when spaces in path (#2508)
• [docs] Prevent mixup for new programmers (#2599)
• [example] Fix chat display in Firefox (#2477)
• [chore] Add gulp & babel in the build process (#2471)
• [chore] Bump engine.io to 1.7.0 (#2707)
• [chore] Remove unused zuul-ngrok dependency (#2708)
• [chore] Point towards current master of socket.io-client (#2710)
• [chore] Restrict files included in npm package (#2709)
• [chore] Link build badge to master branch (#2549)