add jshint to dev test
add jshint to dev test

rohit765/PhysicsJS,wellcaffeinated/PhysicsJS,eric-seekas/PhysicsJS,Luwdo/PhysicsJS,mcanthony/PhysicsJS,griever989/PhysicsJS,rohit765/PhysicsJS,mcanthony/PhysicsJS,pietro909/PhysicsJS,VANITAX/PhysicsJS,pietro909/PhysicsJS,Rawneed/PhysicsJS,eric-seekas/PhysicsJS,Nayar/PhysicsJS,jpellerin/PhysicsJS,griever989/PhysicsJS,jpellerin/PhysicsJS,aldeed/PhysicsJS,Nayar/PhysicsJS,haithemaraissia/PhysicsJS,aldeed/PhysicsJS,haithemaraissia/PhysicsJS,wellcaffeinated/PhysicsJS,Luwdo/PhysicsJS,Rawneed/PhysicsJS,131/PhysicsJS,VANITAX/PhysicsJS